I would not reccomend the super charger at all. If someone made a nice supercharger that was designed with performance in mind, it might be worth considering. The supercharger that you're referring to is very ineefficient, and needs quite a bit of modifying to make it work. Basically, you can buy an engine for just a little bit more money, and have more than enough power on tap.
The Ofna Picco Max .26 is a direct bolt in for the T-Maxx, as is the OS21TM. The OS is a better motor IMO, but it's also expensive. The picco is a nice motor and it's more economical I believe. If you have a 3.3 T-Maxx (or 2.5R) you can put it in and go until you tear something up, but if it's a 2.5 T-Maxx you will need to upgrade the transmission internals, or swap in a 3.3 tranny, to handle the extra power. You're also eventually going to need to upgrade the drivelines.
There's also an RB or sirio (or maybe both?) .23 that's a drop in for the maxx, but I don't know a lot about it. One of our veterans recently sold one, and I REALLY regret not buying it for my maxx shelf queen project.