If your plans are going to boost later, but on a budget, I say go w/ 2.5l w/ low comp pistons(I have some for sale if intrested, check classifieds). Upgrade the bearings, leave the rods and whatever else you can afford after that (heads, etc..).
'99 Silver svt
For sale
19" Axis Neo wheels
3.0 parts, pre-98 trunk,
Check classifieds
bp.powell@comcast.net