i did my engine compartment with this stuff,
http://www.mcmaster.com/#sleeving/=66qy0m
in fact the clamps can be bought thru them too, they do credit card sales mostly, and you can return stuff if you mess up and order the wrong thing.
i have never waited more than two days for stuff i ordered. i haven't used the online ordering i normally just call with the numbers i want. use the black stuff, it is coated and stiffer than the white. makes fishing the wires thru easier.
good luck, fred
ps..... click sleeving and then choose black, it will show the sizes offered, sold by the foot....