You're right, that is a small shower. Most kits tend to be square. Is there any way you could gain those 2" and make it square? You'd have more choices.
Building your own tiled shower isn't as intimidating as it used to be. Check out www.johnbridge.com for some (high volume) discussions by users and pros about tiling things. You may also want to consider looking at Kerdi from www.schluter.com and Wedi from www.wedi.de. Both of those tiling systems are pretty quick and robust...they are waterproof in themselves, the tile is for durability and style.