Mark,
Your idea sounds interesting. Here's a pic that will help you visualize the items that need to be considered for a toilet "redirect":
The gray colored pipe is the water supply. In my opinion, it would be a pain to drill another hole and try to relocate that pipe. A better option might be to graft some flexible hose to it so it can reach the new angle of the toilet. The two bolts sticking through the rubber gasket could be a problem. I'm not sure if they're simply bolted through the bottom of the shower pan or connected to the black water tank. If it's just the shower pan, I think it would be easy to drill new holes, seal the old ones and either source a new gasket or reuse the old one (ours is still in good shape).
Finally, give it some thought before you ditch the shower. I'm still surprised by how much use we get from it. On camping trips with our Tacoma we frequently go a couple days without a shower. We have a great shower system but it's a hassle to setup and tear down the shower tent. With the Tiger, it's pretty common for us to take 2 showers a day (seriously) and we never go a day without at least one shower. It's so convenient to have a dedicated, enclosed, shower/toilet. Heck, I'm probably cleaner on camping trips, now, than I am at home.