"Educate Me" is a very apropos title.
First - the ProVLA is a very useful piece of hardware. However, I would suggest that "out of the box" it is near useless in the mastering chain. It works fine for vocals and even some percussion (I like it on hand percussion).
Personally I modified mine by replacing the existing OpAmps with both Analog Devices and Burr Brown OpAmps as well as replacing the tubes with matched Mullards. In all, the upgrades cost less than $100 and took about 3 hours, but was well worth it. Now, I don't hesitate to use the device for mastering.
A 31 band EQ?????????? Why?????????? Just out of curiosity, when you were visiting others' sites, did you see anyone that was using a 31 band (or any graphic for that matter) EQ? Probably not.
In general, graphic EQs are reserved for live sound guys. You won't find many "high-quality" graphic EQs. Also, a graphic EQ has no control over what you're doing to a frequency other than boost or cut. With a good 2 or 3 band parametric, you can work with minor adjustments at crucial frequencies and get what you need done. Graphic EQs are also notorious for horrible phase mutations and noise issues. STAY AWAY from graphic EQs (unless you do a lot of live sound).
My personal rule of is - If I have to use more than 2 bands of EQ during mixing or mix-down, I have probably recorded something wrong.
The bad news is, good parametric EQs are expensive. As for hardware, your cheapest and/or best bets would be Speck or Toft Audio EQs. For software - there are tons of good EQs available for things like the UAD or TC plug-in cards.
In any case, good luck and enjoy the hardware world! A few years ago, I made the switch to all-outboard processing and I have been delighted ever since. It's a horribly expensive proposition (just think of all the $$$$ in cables and patchbays alone!!), but well worth it!