spend some time searching here, read the numerous threads about full blown builds and several budget builds too. most of them have prices on how much they spent and some even have updated info on how its holding up.
i am going to be going with stock lb7 block,stock piston,carillo rods,ported lly heads, head studs, and few other add ons,100%injector,and five big efi tunes
you can cut your own pistons if you are only going for 850 or so rwhp. what are you doing for air? if you go to the dmax hard parts and look back though the titles you will find a bunch of build threads like mine that will get you started.
Like Henry said LBZ pistons crack. not sure the power level i am at with my build prob somewhere in the mid 700s and i have cut and coated LB7 pistons from SoCal that i bought used from another member on here that dynoed over 1k with them.