I went for MS3 from the very beginning for built-in USB and SD card logging. If you're still on MS1, I suppose upgrading does make sense.
I saved the $100 on the MS3X extension card. With it I could easily wire sequential ignition with COPs, without it I had to source 2 IGBT coil drivers for Ford's wasted spark setup. Since there's just one BIP373 in the kit, and I didn't want to wait for another BIP373 from US, so I just found some IGBTs made specifically for the coil driver application on Farnell.
No need to buy the kit from across the pond, just get a TIP122 transistor, a dieode, a resistor and a mica insulator from your local radio components store, or Farnell/Element13.
http://www.msextra.com/doc/ms1extra/...nual.htm#Fidle