I concur with the sentiments so far. Buying a used engine is a bit risky, I'd do the rebuild and go with quality parts if u can afford it.
Taking the cost of gaskets and labour into consideration I'd spend the cash on the internals so that once its buttoned up you won't have to get into it again if you continue with upgrades down the line. If ur on a tight budget I'd hold off on any items that can be addressed with the motor in. These items can be purchased down the line and installed in the driveway.
If u hold out you should be able to pick up used intercoolers for a decent price.
