I like the Canons but it sure would have been nice if one or two housings fit the whole product line. The way it is now, new camera = new housing. Hermosadive is right about the A70 being discontinued - hell, in a year, the A95 will be old toast too. Finding replacements should not be that big a deal though, as long as eBay sticks around.
My wife has some junky old Breshnev-era Soviet POS camera that I had never heard of - it sure wan't exported to the Western bloc in any quantities like some of the East German cameras were. So just for research, I punched it into eBay, and they had 6 of them listed.
The other option is to find a setup that you like, keep your eyes open, and buy a couple more of the cameras when they go into the remainder bin.