i'm glad you liked the design of the pack and thank you for your kind words.
i/ll try to reply to all your questions and suggestions but please forgive me if i accidentally leave something out (it's 2AM and i'm a bit tired).
my inspiration was a pack made by mchale (http://www.mchalepacks.com/ultralight/detail/Little%20Big%20Packs.htm). i really liked the simplicity and versatility of this pack (and the color combinations of course) and on top of this i tried to fit my needs with the materials i could find. but the big kick was cris zimmer's first pack (http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=41102&skip_to_post=349371#349371), it really gave me the amount of confidence that i needed to start sewing. i always liked the clean lines of climbing packs (although i'm not a climber, i have a very limited experience with the outdoors but i hope to change that in the future) so i'm pretty pleased with the looks of the pack.
initially the plan was to sew two stretchy pockets on both sides of the pack (kind of the stretchy material that the front pocket on the granite gear blaze 60 is made of), i even found some nice brown stretchy material but i could not sew it because it kept on stretching while i was sewing it so i decided to do exactly what Tyler Hoecker said and attach a pocket or a pouch to the right side for my water bottle. i don't have an internat pocket for a water bleater.
as i said about the materials i bought what i found. i don't know exactly what they are. the back and the bottom i was told is some sort of cordura and the face of the pack is some ripstop nailon i guess, both seem to have a pu coating on the inside. there is a big wear-house where they have literally tons of materials but they don't really know what is what (they said that the materials come from all over europe especially from factories that run out of business and wand to get rid of the materials they have in stock). so i just walked around and picked the thickest ripstop they had. they even sell it by the kg (4 euros/kg or about 3$/meter – cordura, and 2$/meter for whatever water resistent nailon you want). so i don't really know what materials i used.
about the day-pack i did thought about something like marmot kompressor or the north face flyweight, but to be honest it's a bit hard to decide because i really like how the small day pack looks on the above mentioned mchale and my curent sleeping bag takes a lot of space inside my backpack so the extra space in the externally attached day-pack woud be useful.
the shoulder straps are confortable but they are a bit wide so they look kinda odd on me (i'm about XS – S men sized)
also thanks Terry for the tips and the link. my bigest problem is that i can't rely afford some high tech materials (the pics were taken at my sister's house and their place looks pretty good :)) but hopefully things will change for the better and your tips could become quite useful.