Adding gauges -Boost, EGT and Transmission temp

Yep, gauges are critical if towing. I would also add the TorquePro app using a bluetooth OBDII dongle to monitor other important function as well as to read trouble codes.

A tuner or preferably, a chip will help, but with stock injectors you're only going to get another 60 hp and 120 ft lbs of torque out of it. The transmission is the weak link, so take care of that with a good size cooler.