Subscribing, would be interesting to see what the OP does and results. I'm in a similar situation, where I worked up to the 7D with 70-200 II (and sometimes tc's). It was manageable from a budget perspective. However going the next step seems to be the high $$$$ pro gear, which is just way beyond my budget. Personally I just suck it up, since I'm not a pro, and live with lower quality pictures in some circumstances (however most of the time I do love the IQ and performance).
To the OP, most of the pictures on your site are excellent! Do you often run into the situation where you are longing for better performance, or was it a one time event?? Does it make sense to spend a small fortune on the high end pro gear for once in a while issues??
The good news is that the 7D sensor and body is pretty old now (Nikon introduced a D7000 and recently the D7100 since the 7D was in the market), so there should be an update relatively soon with hopefully a nice step up in high ISO and AF performance.
So one option may be to suck it up and see what new technology will bring you in your current budget range.
I have so many shots that I look back on wishing I would have shot them with better gear ((my 40d days)) its not funny...buy what you want... 7D not bad but best in brighter light..I have one but the 5D2 and 5D3 takes it two to three steps further on the light side of things and overall IQ....