Sorry to hear about your crappy luck
A decent upholstry shop should be able to do a real ghetto repair on the top for you so long as it isn't sliced up tooo badly. It'll look like arse, but it'll also get you through the winter.
Maybe consider buying a stereo with a detachable faceplate? Tho, that only helps if you're not like me and actually detach it once in a while.
You can get a cheap alarm for $100. If theives really want your stereo/car they're going to get it. But it looks like in this case it was kids and would probably have scared them away. (who steals a steering wheel cover BTW?)
Good luck catchin' them bastards!