Thanks LastButNotLeast, I ended up muddling around the site last month when I posted this and finding that link.
I've ended up with 2 of the ECM8000's that I've had professionally calibrated, 2 boom stands and an Alesis iO2 USB interface. I'm experimenting with ARTA, REWv.5, TrueRTA and ETFv.5 software.
I do a bit of speaker modding as well as solving mode problems, and with 2 mics I'm able to take Stereo Listening Position measurments as well as standard Nearfield and 1Meter/1Watt measurements. I'm having a blast experimenting with this gear and am really pleased with the cost/performance ratio.