Go with the 6MT if you're gonna do forced induction, or upgrading the 7AT to match will likely double the cost. If you don't mind losing the nostalgia of working the clutch (and hell with SRM you've already lost heel-toe unless you just really want to disable SRM and DIY), the 7AT works great on the track. My POV on this is there's 10,000 other things I need to focus on and learn about track driving, and that clutch being out of the picture is just one less to worry about. Every time I've been out, I get at least 1 manual driver coming up to me after a session and asking about it enviously, because they were behind me for a downshift into a corner, e.g. this one:
Youtube video:
TDE MSR-Houston Nov 6 2011 - YouTube