1x p/n 0705368Z01 XTS3000 Keypad Flex $13.42
1x p/n 1585506D07 XTS3000 MIII Housing $68.00
1x p/n 5105385Y19 XTS3000 LCD $85.85
1x p/n NTN8311B XTS3000 Keypad Board Kit $46.00
1x p/n 0904857P43 XTS3500 Rubber Keypad $12.31 (has the cool purple menu function buttons)
Keep in mind that the Model 3 housing does not come with electronics. You could, (if you know how) swap housing electronics. By electronics I mean the speaker, knob and flex circuitry. Search "Panter88" on eBay. He has "complete" (w/electronics) 3k M3 housings fairly cheap, typically around $50. Might take a week to get here, but Lau delivers.
As for the rest, software wise, do a search on Batlabs (
www.batboard.batlabs.com) on how to electronically convert the radio. It's been covered many times. While it won't exactly tell you how, it will give you a good idea on how it's done.