Sprint Blackberry 8330m want to force roam on verizon

Ok so I saw some threads about someone was possibly working on a 4.3/4.5 hybrid that would have the roam only feature, but still have mms capabilities. That would be great, but I still haven't seen that come to fruition. I wondered this if anyone could help me out. If i installed a verizon os onto my sprint curve would the phone think that verizon towers were home? That would be great or if there is anything you could change to make it do that that would be great. Has anyone came up with any solution to this yet? Oh yeah and don't say go get verizon because for one it would cost about 80 bucks more a month, for my wife and I's phones, and two they wanted an 800 deposit where sprint wanted 0, so that wasn't really an option, but I just love their networks reliability.