due to the fact that i'm using input 2 as a sampler return into the Ultra, I cannot split my signal to be: FOH=Output 2, Stage Amp = Output 1. That being the case, I've been employing the use of a parametric EQ between the Ultra and stage amp in order to do just what you're talking about, without those EQ changes effecting the feed to the FOH mixer. This allows me to quickly tweak: stage volume, Hi-pass (to reduce low end "boom"), low-mid cut/boost, hi-mid cut/boost, and presence boost frequencies. I can quickly tweak my tone to compensate for the stage environment, especially handy when there is little time for a lengthy sound check.
Good quality Graphic EQs are easier to come by for relatively cheap money compared to parametrics, but you might be able to score a decent Rane PE15 for under $300 used.