Welcome to the forum. There is lots of discussions on the forum about the AT and wanting to use the LNF or LSJ engine and the 5 speed. To find these (if you haven't figured this out already) use the Search button in the green header in the right-hand top corner of the page. Search AT and most of them should pop up.
As Ark indicated, going with the taller tires, versus stock diameter tires, has a significant loss of torque - somewhere north of 20 percent and likely closer to 25 percent. Being an off-road leaning vehicle, this loss would make the Goblin feel 'weak' at the low speeds it would normally be used at. A turbo wouldn't help much at the low rpm, but the supercharger may have better performance.
It should be noted that the LNF, or better the LSF, mated to the auto would be a better setup - just my opinion - and there is at least one other AT builder going that route. If you have serious questions about the AT and what your options are, call Lonny or Adam at DF. They will talk to you and give you the straight answers - and find out what will work best for Goblin.