Photoflame:
Although I have a different set-up in my studio,
Yam MD-8, which has a self-contained mixer, plus a host of other "black boxes," maybe I can offer a tip?
If your mixer has EQ, I doubt as if you will ever notice the absence of a compressor box.
If you use a good mic-preamp,[as well you can run keyboards sounds through the same mic preamp], I doubt as if you will ever miss a compressor.
I had one once upon a time; it now collects dust in my basement storage area.
As for EQ on your mixer, I seldom move my EQ away from the stright up/down unless I want to tweak a bass track into a fusty, more gritty sound. Although I have used EQ on some vocals to tame down the talent's volume or "tinny" effect.
Rent a good mic pre amp and experiment with it for 90 days; then, hit the 800 numbers and get the best price for a new unit if it fits your ears. I'm sure the results will be pleasant.
Keep experimenting.
Green Hornet