The most basic necesities are PI heads, PI cams, PI intake, and the head changing kit. There are many ways to improve on that but that is the basic set-up and if you can do it for around $1000 by buying off of someone it is worth it.
I saw a set of PI heads on here in the classifieds yesterday for $400. That is a pretty good deal.
you can get them so cheap.....jegs has them for like 400 a head....hes willing to sell his for 450 shipped...and they are reworked and cleaned and just as good as new....so you tell me what the better deal is lol