I'm a kayaker as well as a hiker, and I'll +1 the recommendation to not get a packraft.
Well, actually, I guess I would just encourage you to figure out exactly what you want from your boat. I'll go out on a limb and say that packrafts are for hikers who want to get on the water, rather than for spending a lot of time on a Great Lake, if that makes sense. Their primary attribute is PACKABILITY- you can easily haul them to remote spots in the backcountry. You mention hiking to boating spots but only as an aside- it seems like you're more interested in boating. (If I'm wrong, please correct me.)
So from your description it sounds like you're more interested in getting out on big water, and not so much on hauling your boat to some remote stream. If that is so and, as I suspect, you're really just getting ready to bite off on owning your own boat, then the issue is "what boat is right for you?"
You mention having to transport it, but it doesn't sound like you're talking about CARRYING it very far most of the time. You just need to store it and get it to the water.
Thus, there are two good options (assuming that I'm correct and that you really aren't looking for a packraft):
Folding kayak
Inflatable kayak
First, folders: http://www.foldingkayaks.org is a decent web forum. And "folding" is really a misnomer- they don't fold per Se. They use a disassembleable internal skeleton on which you place a hullskin of some sort, just like the Inuit did. I can assemble mine in about 20 minutes, and mine is one of the more awkward ones.
Folding kayaks tend to be more expensive. I have one, a Long Haul Mk.2. The Klepper and Long Haul boats are probably far too heavy for your purposes, unless you just want a Long Haul Ute or somesuch:
http://www.longhaulfoldingkayaks.com/boats/ute.php
But the Ute is their SMALL boat and it weighs 21kg! The Kleppers and Long Hauls are hugely over-built expedition craft, meant to take all that you can throw at them, in gawdforsaken locations without support. My Mk.2 is 41kg. Doesn't sound like what you're looking for in ANY way. Their varnished wood frames are works of art- it is not unheardof for their owners to mount them on the wall to admire.
Feathercraft is the elite of folding kayaks, but you certainly pay for it. They make a few smaller/lighter boats that might suit you perfectly, like the K-lite and the Kahuna. Bonus- made in Canada! http://www.feathercraft.com. Most of their boats store in a single backpack, so they are easily storable but not packable the way that a packraft is. Again, these are NOT for packrafting, but I'm not sure that you're really looking for a packraft. Again, correct me if I'm wrong- if I am then others have already given you good advice.
An affordable option is a company called Folbot. They tend to be of lighter construction than the one's I've already mentioned, but as long as you aren't taking one on months-long arctic expeditions they're actually great boats (and there ARE people who have done arctic expeditions in them). They are also pretty easy to repair and work on yourself.
http://www.folbot.com
The Citibot (24 lbs) might be what you're looking for- a bit more expensive than an Alpackaraft at around US$1100, but a HELL of a lot more seaworthy on an open lake. The Cooper is significantly more expensive but if you're seriously considering hitting open ocean at some point it's a much better choice. The Gremlin and Kiawah are somewhere in between. Folbot has a reputation for AMAZING customer service, and there are many accessories and add-on equipment available for them. They've been around forever.
There are other folding boat manufacturers, but these are the big players. If you're a MYOG type look into Yostwerks: http://www.yostwerks.com He is sort of THE MAN when it comes to home-building folding kayaks, and the process is easier than you think. It involves cutting out ribs from HDPE (the plastic kitchen cutting boards) using his templates, and then bending the gunnels onto the ribs. I swear to God that someday I'll make one of his designs.
I'm less knowledgeable about inflatables, so give me a moment to refresh my memory…
Sevylor mostly make cheap stuff more akin to pool-toys, and I wouldn't trust them myself, but if you're really averse to anything but calm open-water paddling something like their Pointer might appeal to you, if only because it's cheap: http://www.sevylor.com/Pointertrade-1-Person-Kayak-P2041C41.aspx
Innova is sort of THE name in expedition inflatables. They tend to be rugged. IIRC a woman paddled one down the Congo, once, or something. Many applicable options, so you'll have to check them out yourself:
http://innovakayak.com
But the Safari or Helios look like your thing, weight about 25-30 lbs, and cost only fractionally more than an Alpackaraft.
NRS makes mostly whitewater boats, but also some ocean kayaks. http://www.nrsweb.com They weren't really what I was looking for, so I never researched them much. They also tend to be rugged.
Advanced Elements makes some interesting designs, too: http://www.advancedelements.com
The AdvancedFrame and AirFusion look interesting, but I can't claim to be knowledgeable about them. (Or any other inflatable, honestly. I'm a folding kayak guy.)
Since you mention never doing technical whitewater you could get one of these (admittedly more expensive) folding or inflatable kayaks to meet your Great Lakes and ocean intentions, and a packraft from one of Alpacka's much less expensive competitors for packing.