Video card has 64MB memory (does this matter, even?)

Not for Poser 4. Or Pro Pack. Or P5. Maybe (maybe) Poser 6, but that remains to be seen. DAZ|Studio will have 3D hardware support, but this will only help during the composition process. True renders are software-driven, and dependent entirely upon your processor speed and amount of system RAM.

1) Does this rate seem normal to Poser people, or am I doing something wrong possibly.

Sounds about right to me, given your hardware, render settings, and the elements loaded in the scene.

Enjoy the speed while it lasts. Eventually, you'll be building increasingly complicated scenes at DVD resolution, where each frame takes minutes to render, and will find yourself taking up productive hobbies like needlepoint to pass the time while waiting for "that next animation" to finish.

2) I have two other applications on the way to me, Motion Builder and trueSpace 5.2 and wonder if these programs can render faster than the Poser 4 engine?

Not likely. The P4 renderer is one of the fastest around, mainly because it's so limited. You start adding features like motion blur, raytraced reflections, depth-of-field, etc. and it really slows down the renderer.

From my days with earlier versions of trueSpace, I can say with some confidence that it'll be slower than P4. I can't speak from experience with Motion Builder, but I know that it's primarily an animation tool with an advanced real-time preview display, although it does have some sort of render engine, also.

3) If I were to buy a rig just to render, what are the specs to go for?

Ultimately, it'll depend upon which software package you choose as your renderer. Some of them can make use of dual processors; others, like Poser 4, can't. As a general recommendation, build a rig with the fastest processor available and as much memory as you can afford. The graphics card won't be of much use during the render itself, but can help during the scene-building process if your software has 3D hardware support.