Start from scratch or buy used?

Alright guys well a lot of you already know I am planning on doing a Turbo Ls/Vtec and I was thinking today. My total right now is very very very high. I was curious if I should keep going with all new parts (used block and head which are in good conditon) or should I buy a used Ls/vtec maybe one that has been turboed and rebuild it? Would it be worth it or should I just go new? I am hoping to put down about 450HP at least. If you want to see my build list it is here: http://g2ic.com/forums/showthread.php?t=146123 Please Let me know what your opinions are on the subject. I know rebuilding is risky but if it is a full rebuild done by a shop?

no one has a comment on this?

well

if you rebuild it, how much are you saving, and are you going to do it or what? jw

I am going to have it all professionally built. This high of a motor I don’t wanna mess something up. I currently have a 91ls block with about 190000 on it. but either way I am sleeving and boring the block but I was curious if perhaps I should buy used and maybe save a little on some parts. I don’t know how much I would save. Right now build tally is at 12+ thats for using the block i have