Have you already bought the new power supply? If not, get a complete case instead. Usually it\'s about $10-$20 more to get the case with power supply, instead of just the power supply.
This way, you won\'t have to worry about whether it\'ll fit right or not. If you must have the current case though, buy everything you need except for the power supply. See if your new motherboard will fit. If not, you gotta buy the case. If so, just swap out the power supply (assuming it\'ll fit in the gateway case, of course), and that\'s it.
