If you want a landslide, go with landslide21. it's got an SH21 in it. I was in the same delima as you were. I had 0 experience with nitro so I took the easy route, singlespeed volcano. parts are very cheap on any of the trucks if you go plastic. upgrade the important ones like engine, shocks, direct drive etc.

on the other hand with aluminum, I'm talkin to my CAD guys and ask if they could do a simple design with stress test with aluminum and where the weak points would be. It'll be interesting to see. My theory is if you have aluminum front lower and upper arm, the weakest point then will be the hinges. hinges cost about $2.50 vs $4 for an arm. like chevy mentioned, if you bent the arm, you're basically screwed and I also dont know the weight of the aluminum. plastic is flexible