I have the SBD kit and it's been awesome so far. Just took a road trip from OKC to Houston. All temps were great and I averaged over 28mpg driving fast. Had a blast all week with it.
Power is good and delivery is nice. Makes all the cool sounds. I'm on stock clutch and fuel for the time being. Drivability is a dream. Should make 260-300whp depending on your mods and fuel quality.
You'll just wanna pick up a gauge or gauges. I like my p3cars + innovate wired into the aux port. An ECUTek cable us a nice investment too. SBD also has a coupon code good through the end of the month.