The Lehners are indeed nice motors and I've wanted one for a long time, but they are hard to get right now. For a truck and 4S lipo (or the nimh equivalent), I'd go for the 1940/8. For 5S lipo, I'd go for the 1940/9. You could just always go for the 1940/8 and run it on 5S when you want to get stupid.

As for the controllers, yes you have choices and each has its pros and cons.

The Quark is probably the reigning king of controllers. I too have been in the market for a better controller and have done a bit of research. The Quarks are know for being very smooth and will handle up to 5S lipo as well as any two or four pole motors. The downside is that they run hot and do need a heatsink and perhaps a fan to stay cool.

The MGM Compro is reputedly a good controller also. It will do up to 5S lipo, runs cool without a fan or extra heat sink, and will run two and four pole motors. It just isn't as smooth as the Quark, although I never saw mine cog with any setup that I had. The programming isn't difficult either. It just takes a bit of getting used to. I had it within 10 minutes. Unfortunately, I believe that I got a defective unit and had to send it in. I'm still waiting to get it back before I make any final judgments.

The BK controllers are very simple. There is almost nothing to program. I found that running it was very abrupt. I mean, there was no easing into the throttle. One second it wasn't moving and the next it was hauling butt. Ours fried within 30 minutes of installing it, but I do have to admit that it was a part of a kit that we got from FineDesign and the esc/motor combo that he sent us was likely not a good combo.

Knowing what I know now, I'd get the Quark and deal with the heat.