How much room do you have on either side of the compressor cover? The hotside should be roughly the same size. If it fits, go for it. Then when you build the bottom end, you could go big, hta35R
If all else fails, I say go for the sleeper 16g from forced performance. Slowboy Racing makes the bastard 20G, and they are aweful to work with and you should not give them any of your money. See their thread in the intro section for more details.