definitely, you'll see lots of them for sale in the classifieds. As for size, i would get a .690 or .692 bore size or both, and a 14" overall length.
Other than an u/l, you could look at a barrel kit like the pipe kit.
well i was having a look on slothball and they seem to be selling a 14" or 16" cant quite remember with a .688 bore, cocker thread for £35.
the question is would .688 be ok?
The bore size depends on the paint you're using, that's why you need a choice of sized barrel backs (this is the only part that effects the paint).
A .688 (standard size) will probably be a bit small for the paint used in this country, a .692 would be a better choice.
Have a look in the classifieds section in this forum, you'll find quite a few for sale and save yourself a few quid.