Alright, in your case I would go with
1) TC Electronic G-Major multi effects unit with a G-Minor midi control pedal. It is pretty cheap and has all the effects you will ever need, outside of wah, distortion, and talkbox
2) BBE Sonic Maximizer, they are cheap, and they make your tone sharper and less cloudy, definitely a good buy.
3) Furman PQ3 or PQ4, just a simple rackmount parametric EQ, great for scooping mids or getting those Dimebag-like tones
I think that is about all you would really need, maybe get a cheap Furman power conditioner, but that is it. It would definitely add to your tone spectrum.
Gear: G&L Rampage, Mesa/Boogie Mark IVA, Custom Avatar Vintage 212, G-Major, Ibanez TS-9, Morley BHII Wah