I have these pistons, Mahle Powerpak 930256252No. Pump gas will be fine.
What pistons are you going with?
What rods are you using?
I had the rotating assembly balanced and they added a bit of weight to the crank to make up for it plus a fluid dampener which should help a little tooI see nothing wrong with those parts. The rods are a tad heavier than stock but to have that peace of mind that they wont break goes a long way. Might feel a slight vibration on the low rpm's... should be fine. Wont be the 1st engine with vibration, wont be the last.
Are the comp cams off the shelf?...not reground?