.. wondering whats the best site to play with this balance.. or do i just need to add more to it just to be safe?
There is no safe balance when it comes to gambling especially when greeds come on play. I just advise you that if you deposited that and you make it to the minimum withdraw limit of the gambling site hit withdraw and re-deposit again. And if you already lose that 100k sats don't ever chase to recover it fast because what would happen is you will lose more and more.