The Tactical .22?
As far as I understand from what Mossberg says, and from what I have seen, anything thing you can mount to a standard picatinny rail will work.
So, for bi-pods, there are quite a few options. A couple that come to mind would be Harris or Yankee Hill. Another option is a picatinny mount with the sling swivel stud, and then the bipod can mount to that. There is a thread on here with a couple of bipods mentioned;
http://www.mossbergowners.com/viewtopic.php?f=38&t=323
based on looks I like the Accu-Shot Atlas.
I think the carry handle comes off the Tac .22? So again, anything that will mount to the picatinny. So are you wanting a scope, or a red dot holographic, or reflex?
Mags, I dunno, its a 702. If you can find anyone making like a 30 rd. or something for the 702, you should be in good shape!