Yes so originally I bought a 6MB voodoo 1 card. The reason was that A) it matches the era better and B) it avoids any problems.
Now that I've learned that there actually aren't that many problems and seemingly all can be avoided I thought the v2 might be a better option.
The MMX range came out in late 96, and the voodoo2 in early 98 so there's only 18 months of a gap and it doesn't feel wrong to have upgraded to a v2 in a 233MMX system at all. Not to the point where I would feel it's wrong at least.
I think this thread has now answered my questions on it. The right thing for me to do is keep an eye out for a voodoo2, and should I get hold of one I will pass on my V1 to offset some of the cost.
I know they come in 8MB and 12MB. I'm not sure the 12MB is warranted at all, but if it is I could just upgrade an 8MB. So I'll be looking for an 8MB V2 I think.
So thank to everybody who contributed on this thread. I feel my voodoo questions are answered. The voodoo3 is not something I should consider, I want to be able to change the 2D card, and voodoo2 in SLI doesn't seem like it would yield any performance gains that would be worthwhile on this system.