T8.1 upgrade kits are about £100, you get the barrel, FS mag, new bolt and spring, and about 16 FS rounds, not cheap.not first strike, but you can buy the upgrade kits from lips. think they were about £40 when i asked them about it but that was 9 months ago.
http://www.ukscenario.com/forum/viewtopic.php?f=71&t=36423
I can vouch for just how anal this guy is with making everything just right! And he's never used the damn thing in anger!ive got my tib8 with first strike conversion kit up on my for sale thread
http://p8ntballer-forums.com/threads/invert-mini-l-e-virtue-eyes-lurker-bolt-pbt-barrel-kit-tib8-bits.157757/page-2#post-1425979