You will kick yourself in the ass over and over if youre putting in pistons and dont go forged.

Wait a bit, save your pennies, hone the block and get standard size forged pistons. It will be the best $400 youll ever spend.

If new pistons are going in, you may as well do it right. If you cant afford to go all out, at LEAST replace the cast POS' with forged pistons. Youll benefit more from having forged pistons than a lower comp headgasket.