Here's what some of that stuff means:

SP = slight upgrade from original EVO, includes caster front arms
N = Narrow. Comes set up narrow in the box, parts to convert to wide included. Perhaps the least important factor, since you can easily change it.
MM2 = Mid Motor mount 2, newest version of plastic mid motor pod. Most 98mm cars will run a MM, 94mm can run a mid mount or an RM (rear mount)

When choosing an EVO, some of the special editions that come with aluminum motor pod and/or ball differential are a good deal.

Mini Z can be set up at wheelbases of 86mm, 90mm, 94mm, 98mm and 102mm. 102mm are all pretty much prototype-style cars, 24hr Lemans type racers. 98mm seems to be the sweet spot for GT cars, with the best performing bodies usually here. 94mm has many very popular bodies, many of which are rare and out of production. 90mm can be really fun, but requires a different approach to setups than longer cars. 86mm is kind of a specialty wheelbase, usually run only by someone with a special car, like a Porsche 935 or a Lotus Elise.

You will need tires and T-plates. Whatever bodies you buy should come with the wheels you will need, or at least you would need to know which body you are using to know which offset wheels to order. For T-plates, the larger the number, the stiffer it is. I like 3 and 4. I would get some tire tape too. And 3+ sets of rechargeable AAA batteries and a good charger.

Those things should be all you need to get going.