I'm pretty much in agreement with much of your post, with the exception of the comment about the VIA Apollo Pro.
Provided that you have the Pro 133A chipset, performance isn't THAT bad. However, it's a moot point, since VIA doesn't currently offer the Pro 133A chipset in a dual config.
My current recommendation would probably be a BX board, since it has the fewest shortcomings. However, that's hardly a stellar recommendation.
My experience tells me that the next good SMP board will NOT come from Intel, since they insist on shoving RAMBUS down everyone's throats, instead of going with the much more logical DDRSDRAM. Once VIA releases an SMP capable chipset that mobo manufactures implement, things will get cooking. Unfortunately, I think we're not going to see a chipset for the P3 come out of AMD, since they're devoting full support to the Athlon (might want to look into a dual-Athlon setup once they release a SMP capable chipset).
Keep in mind that you don't double your system performance by adding another CPU. Even on programs that take advantage of SMP, you only get about a 70%-85% performance boost, generally. Add more processors, and the returns diminish further.
I'd honestly recommend that you go with a very fast single-CPU solution. Use the money you save on the motherboard and extra processor, and get a kick-**** video card and load the mutha up with RAM.
----------------------------
I am Jack's raging inner child. Without me, Jack has to deal with the pitfalls of reality.