Go Tekno. Kits are harder to find anymore and as you stated you're building it the way you want from the start. Tekno makes premium vehicles anyhow. Parts may be more difficult to come by but you can find a source to order from.
Arrma would be a close second for me. They're part of the Arrma / Durango group and Team Durango, just like Tekno, makes premium race vehicles also. I'm seeing more Arrma products at my LHS and I've been taking notice of the Mojave 1/7 SC truck myself.
Lastly, nothing wrong with Traxxas in general but I've personally "outgrown" them. I have an old TMaxx 2.5 that I've held on to and it's my only Traxxas vehicle and my last running nitro vehicle as well. Parts are abundant for the TMaxx platform and I honestly have fun driving it. Otherwise I wouldn't consider investing in a new Traxxas truck. The XMAXX looks interesting but for the same money I have been window shopping a Losi and Arrma product; I'm just having trouble deciding on which one to choose.