Going with the truggy is definitely the way to go. I have both, the truggy and buggy, and the truggy definitely gets more time on the track. It's just more fun.

For the setup. I'm only going to talk about what is available now and will not speculate about what may, or may not, be available tomorrow or next year.

For racing 4S is probably the best way to go in terms of weight, runtime and power on tap. The only problem that I see is the runtime that you require. I run an 8Ah pack and that's good for a solid 30 minutes on the track with my setup.

First the power train. Since you say that you want the best, I'd go with either the Neu 1515/1Y or the 1515 2.5D and Quark Monster Pro esc.

The 1Y is a 2200kv motor and the 2.5D is a 1700kv motor. Of course, the 1Y will be faster on like gearing than the 2.5D, but you can make up for some of that speed loss through gearing and the 2.5d will get better runtime. Most opt for the 1Y. The other benefit is that the 2.5d will be more 5S friendly, should you ever decide to go that route. Many run the 1Y on 5S, but it does get a bit hotter than the 2.5d on 5S. Although I've been teetering on what I like lately, if I had to make the choice now, I'd go for the 1Y. Under load it should deliver about 2000kv and I think that's about perfect.

As for the esc, the Quark is, unfortunately, the best going right now. It is smooth and runs the Neu motors very well. The problem is that many have had overheating problems with the Quark. This can be fixed with Mike's Quark heatsink and some thermal epoxy. If you have the internal heat transfer problem, you'll have to mod the Quark with the addition of an aluminum heatsink. It isn't hard to do, but some have found it necessary.

You could also consider the Compro controllers by MGM. They are very solidly built, but I've had nothing but trouble with mine and MGM is in the Czech Republic, so tech support and warranty repairs take forever. I bought my MGM a couple to a few months ago, and I haven't had it in my possession for more than a few days yet.

If Mike makes a motor mount for your vehicle, I'd jump all over it. It takes a lot of the pain out of doing the conversion.

You also want a ubec to power the radio and servo.

As for the battery, get the best that you can afford. I like the Kokam and Flightpower packs, although the Flightpower packs are widely used by those that can afford them. Very good batteries. Whatever you do get, just be sure the make note of the dimensions of the packs. They vary from manufacturer to manufacturer.

If you already have the ice, go for the Hyperion LBA10 balancer. It works well with the ice.

Back to the 40 minutes of runtime. You could go for a 12Ah pack, but it's going to be big and heavy. Whether you can run it will depend a lot on your track. For me, it's just too much and totally screws up my handling.

The best bang for the buck batteries around that deliver performance too, are the maxamps packs. They are good guys and will build you a pack to whatever specifications that you need, which is something that you can't do with the "better" brands of packs. I run the maxamps 4S2P 8000mAh packs and have never had any troubles with them.