Thermorests are supposed to be self inflating. I open the valve on mine and leave it a few minutes then just a couple of breaths to firm it up. Mine is full width but doesn't extend much below the knee. I sleep like a baby on it - but in truth I don't remember ever crashing on it without a few beers first.
Since someone asked I bring
2-3 man Tent (usually something you could get at crappy tire)
Sleeping bag
Thermorest
Folding camp chair (we usually camp rough/vagrant so no picnic table)
Ukulele in a small coffin I made for it
All of the above goes in a hockey bag I strap on the seat
In the saddle bags I pack clothes (always too much) running shoes, tinned fish and crackers, beer and periodically a one burner coleman and a pot w/ lid (mug and coffee inside)
The tankbag has stuff I want handy - water, camera, sun block, sun hat and bug hat/shirt.
Cooking usually consists of hot dogs cooked on a stick and opening a tin of smoked oysters or herring fillets.
Might I suggest canned Ravioli + soups. Works much better with a fire though.