I would just use the 545 that the hemi came with, thats what I did, easy (either way you have to do floor pan mods). Has a speed signal an auto meter speedo can read, and a tach signal an auto meter tach can also read. I used an 03. If I was to do it over, I would have dumped the 03 computer, which has two, one for the engine and one for the trans for an 05 computer, and put a 500 hp tune on it and away I go. With an 05 you need an adapter for the tach and speedo, but they make em. I guess With the tti's it is supposedly 400 hp, but you touch the key it is running and it idles great and will run for 200,000 miles. Try that with a carb engine, ha ha, yeah right. I can hook the scanner up to it and see what is going on, that too is nice. I used a hotwire wire harness, Chris was very helpful, will use him again.
Right now Im finishing up the stainless fuel tank I made, it is turning out sweet, I used the rams fuel pump, so it was designed for this engine.