Guages First!
Given that you have the ETH engine, get the guages first.
The ETH runs hotter EGT's stock than the ETC engine, so you are less likely to be "lucky" on EGT when BOMBing.
I bought my guages after one BOMB, but wish I had done it first now.
THEN.....
Get yourself an EZ box, boost elbow, and maybe a set of injectors and voila!, you will have a MONSTER towing machine.
You could go with other boxes of course, but for the simplicity and ease of removal, it's worth it given how much extra torque you get out of it.
My . 02
Shawn