The ball-bearings are basically a sandcaster.
As for the beams vs missiles, assuming your beams can also damage ships (and they can probably at least blind them), it comes down to whether X tons of beams weapons (including power supply, radiators, and so on) can kill X tons of missiles (including launchers, etc. in that tonnage of course). If the missiles can't get through, you're better off with the beams. If they can, missiles will at least have a place, if not dominance.
I just run with TNE's detonation laser warheads and the assumption that point defences mean no contact missiles in space combat. I do need to get round to designing some non-atomic stand-off warheads for civilian use (which would also have military applications because they'd be damper-proof).