Those props should be fine.

Always avoid adding dead weight to a plane, so if you can get the right CG by moving the battery, then do that. If you still cannot get it with the battery moved as far back as you can get it, then you can either buy a larger capacity battery that weighs more, or you can add some dead weight. If you get the bigger battery, then you are still adding weight, but it is not just dead weight, you now have a battery that will last longer.