The MI3 would be a great choice.
The suspension is durable (same as the MI2). Plus, an added benefit is that if you do snap and arm or hub, their design usually keeps the parts together long enough to finish the race! For spares, just grab a couple extra arms, hubs, and knuckles. And as you own and continue to run the car, periodically pick up extras to have in your box (ie 5x10 bearings, hinge pins, etc.).
The spool is actually a great way to go. But if you need a one-way, Schumacher's is very tough. We ran it in our car at the 24 hour Guiness Book enduro. It's still in great shape!
As far as product support and set-up info, there's a lot of companies doing a good job, but none better--and more accessible than Schumacher.
And with all that said, it's got to be one of the sharpest cars out there!