I think it's just a momentary SPDT switch. (It may be a DPDT switch, though; check how many connections it has). I would not replace it with a non-momentary switch as should it get accidentally left or turned on for an extended period of time it will quite likely burn out the coil on the latching relay.
It shouldn't be too hard to find a suitable switch online. If nothing else, a company like Mouser or Digi-Key will undoubtedly have something suitable, and probably the same size or very nearly so as your existing switch.
This switch from All Electronics would work fine, too, but is most likely a good bit larger physically than what you have. A power window switch from a junkyard might be a workable alternative, for that matter.
A pair of momentary pushbuttons might also work out okay in a pinch. Pressing both at once would not be a great idea (but I don't think would cause harm).