I don't think the limiting factor is Hardware...
What you need to look at are what are the limits of the programs you are going to use. Lots of programs run slower on multicore PCs because they are not ment to be used on those, in some cases the ability is built in but not all. Also the versions you own and plan to install my not work with the new hardware, it might be for windows only etc. So the first thing you will have to do is research out the software you intend to use, even if you are buying all that new you need to look it up and spec it out.
Once you know what the software can be used on, and which ones you will have to buy for the different OS versions, you can start to look at HW. This also means you have to plan out the intent of use better, what you have now is pretty vague. You also have to look at what the ppl you will be interfaced with use, if you can not export to a format they can use or see then you will have other issues as well.
So well super high end HW sounds nice, unless you do work for a major studio or company you will have to look more middle stream.