http://www.haynes.co.uk/forums/showthread.php?t=2459 - handyandys thread on the subject.
Do you not have welding plant? Why not build your own, saving a few hundred quid in the process?
How long is the Talon waiting list? If you have waited a month trying to decide where to get your chassis plates from, then surely waiting a little longer for a chassis shouldn't be a problem.
'If' I were to buy a chassis that would have been the first thing I got, because whilst waiting for it I could have been cutting the chassis plates, if they were'nt included on the chassis.
I cut the vast majority of my chassis plates myself, and the only bits I bought in were the 10mm plate for the rear uprights and the 5" tube. It is very satisfying, and a great learning experience
Sean