Replace screen/digitizer OR operating system???

My screen issues don't seem to be common around here. It "works" most of the time, but the colors will sometimes scramble or invert (like a "negative" photo, but all in color), or the display will double (half on top, half on bottom), or reverse altogether. (It's actually kind of fun, trying to text like this!) No damage, moisture or otherwise, so I'm not sure what caused this. I've had the phone for about 18 months so it's not covered by warranty. (And for the record, my last Samsung phone had major display issues similar to this, with the weird colors and doubled display.)

My friend gave me his Impression which "works fine" but for lack of operating system. I've tried searching for the software but I'm coming up empty. Is this even possible? It just seems like it'd be an easier fix (if I can get the software) versus taking the phones apart and swapping the screen.

Well flashing is free and if you have the boot loader screen you really don't have a choice. Try it and see what it looks like after the flash. You have nothing to lose at this point.