So it's been a while since I posted this question. Thanks for all the advice. I actually went with a Flea 47, SM7 and a Mojave MA-200. Haven't actually used the Mojave on vocals yet but plan to soon. Been using for overheads and room mic instead. There's sooo many great options to choose from these days.
I heard the Flea against the Slate VMS at a shootout in a local studio. In blind test I picked the Flea. It just had that extra something. Who knows, if different singer, perhaps I may have picked the Slate instead. It is really cool.
I'm still wanted to try out a 251 style. That Manley Gold sound awesome.
I also purchased a capsule from Tim Campbell to build a C12. If I can ever find the time!