This is only a tough one because EQs have a lot of components. Personally I use an MXR 10-band in my effects loop on my gig amp. I have it just before the reverb (which is last, except for the noise gate which is off most of the time anyway).
I find that I don't change it very often, and it really isn't set very drastically. It just adds a little clarity kind of like a buffer. So if you just had any kind of small gain boost (a BMP with LPB1) with a tone control that might be all you need.
http://tagboardeffects.blogspot.com/2013/08/bmp-tonestack-w-lpb1.htmlThe main factor would be if the boost gives you undesirable noise. Then I might see what the buffers can do. The Cornish are good. Maybe try one coming right off your guitar and another one right after your last pedal leading into the amp.
Or there is always the Klon(e)
. .
If a boost works but adds noise, you could try adding an LPF at the end and roll off the uber-highs until the hiss is gone.