Today I received a few bits and pieces from T-Rex Racing in Dallas. I ordered the front and rear axle slider, plus the exhaust slider. Good quality hardware, the sliders look decent and the install was straightforward. I want to install a frame slider at some point, but I didn't like their offering. I like the Sato Racing ones better, just going by looks.
edit: Regarding the ECU flash redline increase, yes, it appears to have more RPM headroom, so you can rev it higher. Haven't tried out where the rev limiter kicks in now, but the needle went into the red without issue.