Well man you went from new to installing a shift kit to full builds, impressive!
I like the springs Transgo supplies, all 3 in one bore lol. Some kits just use spacers, which I would think gives a bit of a weird shift feel, like a soft initial apply then a hard bump. Haven't tested that but I like having stiff springs and shims to back them up. At least with my 02 half the reason I put it in was because I had slower shifts as it got warm, I bet my 06 will do more with the standard transgo than my 02 did being the 06 trans works perfectly. And yes it's supercharged. And I hope I don't "have" to go in there at any time, I'm not gonna be too crazy on it. My 02 would take anything you gave it, but that's because it's N/A lol