I think I have now canvassed this issue completely. Here is what I found…
Available regular length pads in a wide width:
From above – Kylmit Static V and Insulated Static V
http://www.klymit.com/index.php/products-1/sleeping-pads/static-v.html
http://www.klymit.com/index.php/products-1/sleeping-pads/insulated-static-v.html
Pretty cheap, heavy for R-value. Regular Static V is probably the best one season, summer option I've seen.
Nemo Cosmo Air and Cosmo Insulated
http://www.nemoequipment.com/product/?Cosmo+Air
http://www.nemoequipment.com/product/?Cosmo+Insulated
More expensive than the Klymits, and even heavier… R-value not listed however. Insulated option may be warmer than insulated Klymit, but is still 200g heavier…
Stephenson's DAM
http://warmlite.com/down-air-mattress-alone
This seems like a good option if you want a winter pad only – range of lengths and widths available. Designed to go inside their bags, but seems fine for use outside. Weight to size ratio seems similar to the Exped Downmat UL7.
I'm considering this (as I do want a winter pad). However the Exped is a lot more engineered, ie better pump and valves, material (major manufacturer vs cottage), rectangular (personal preference for side sleeping), a little lighter if I can live with 20" width, and similarly priced (for me in Australia). Basically I'm going to jump on the downmat in the next little while and if I still would like the extra couple of inches I'll buy the 70"x24" Stephenson's…