Keep in mind, with the Thunders there is a good chance you'll be sliding on your wheels on tail and nose tricks on account of those hangers being further out on the baseplates. With the Indys, seeing as the hangers are set inside the baseplate more, you're going to be sliding on metal with nose and tail tricks. I prefer the sound and feel of the metal, and find it less likely to stick or get little flatspots.
From one OCD dude to another, here's some advice: pick one and stick with it, and trust you made a good choice--Indys and Thunders are both sick. You'll adjust to the slight differences and everything will be OK. Sell or give away the other set of trucks or you'll be likely to keep switching that shit on and off until you rip your fucking hair out from obsessing. That, or stick them in a fucking closet and don't even look at them until you're down to the axle on the ones you choose to ride.
*edit
Yeah, Firebert above my post has a good example of what I mean about sliding on the baseplate in his pic.