So, assuming a similar course of evolution elsewhere, it doesn’t seem a stretch to me that there’d be a bipedal reptilian humanoid, probably with a prehensile tail (that third, in-the-way limb).

I’ve always figured that if man’s shape is basic (and I do, hey, I’m biased), so are the following:
* Light sensitive organs would be on top
* Olfactory/chemical sensory organs should be on top AND elsewhere (near the ground)
* Pressure/vibration sensory organs should be on top AND near the ground
* Nutrition intake should be on the upper half (let gravity do its magic)
* Excretory organs would be lower
* Communication organs would most likely be on the upper half
* I’ve always thought that the brain is in a weird spot. It’d make more sense to put it in an armored case in the middle of the body.

I figured a “body” with most of the digestive and nervous systems would make the core, supported by two limbs, and maybe a tail, with three appendages: “arms” and a “head” (or maybe combined into two limbs). The “head” would carry mostly sensory organs – two of them would be best! Reproductive organs on the limbs makes sense too, or maybe one or two more limbs for those.