I've read bad things about the cvec one and the other one won't work. You need a new exhaust and header designed for a side exhaust engine if your going to run the wasp 18.
This header
Old Maxx Header and this exhaust
Old Maxx Exhaust and this gasket set
Rectangle Gasket and this coupler
Coupler should do what you want. I have an off the wall one that I got from my LHS that sux which is one from Power Racing. I can't find it on their site and thier site kind of blows anyway. But it's pretty much the 4 things I listed, but mine all came in a kit.
As for the no reverse, your right, I don't have it. I took reverse out almost 2 years ago and haven't missed it once. You need to get a FOC (forward only conversion)
Maxx FOC that replaces some crap in your trans. I don't think you need to remove reverse though to move the receiver, but you might. I would, it improves performance and adds more longevity to the trans gears. It takes away that jerking motion the truck does when your starting off.
As for pics of how I mounted the receiver, I don't have any worth a crap. I'll take some tonight for you.
My wife needed the computer, so I had a chance to snap a few pics for you. The truck is dirty and I'm not about bling factor, but they are attached. I include one of the whole layout, in-line exhaust, throttle servo linkage, fuel tank mod and reciever stand off. I'm using a racers edge aluminum servo mount to screw the steering servo and reciever into. If you need larger, clearer, I can start a thread and post them or email them to you.