There is a third way, grasshopper!

The KB pistons will remove about 90 grams per hole. So yes, balancing would be advisable.

Stock pistons will require something like 0.060 off the decks. That isn't free.

The Third Way
The Speed Pro H116CP is a stock replacement piston with same weights as stock. It has a 1.660 comp height so it'd end up 0.005" below a standard deck of 9.578. Much as I hate to recommend a heavier product, I think this is the best way. The pistons cost exactly the same as the KBs.

When you're getting prices, if you ask for a price of squaring the decks you will get one number. If you ask about squaring the decks and removing an extra 0.060, you will get a higher number. So get your options written down.

R.