Hi Tony,
I too used to play in a loud originals band; big, dirty metal riffs in drop c tuning with two loud guitarists etc. you know the score... I was using 8x10's and a sansamp, with the old smiley face eq... More recently I have also begun playing with a covers band, and currently use a little mark ii driving 2 112 hartke cabs. I carried my old habit of the smiley face eq into this scenario, and have only recently realised it doesn't work! Not only did it feel like I was lost in the mix, it didn't really seem to add much to the overall band sound. So now, I have introduced the midrange, and plain detest the sound on it's own, however, I can now hear myself, and the sound in band context sounds perfect (to me!).
So that's a whole lot of waffle that doesn't even mention aguilar! I guess what I'm getting at, is that I think 2x112 cabs will suit you fine, provided you don't overly scoop your midrange? The Th500 is the same wattage is as my little mark, so should be spot on. Also, the load ins are a thousand times easier and quicker...
Hope this, in some bizarre way helps your decision, best of luck!
Rick