$85 delivered to my door. Who knows how long it will last, but heck, it might get us through a few more years (or not...who knows?)

So, in summary:
Stumble at idle, followed by CEL coming on briefly while driving 30-45 mph, followed by just wouldn't idle (wild surging), rich running, and code 1222 with CEL lit fully, all in a span of about 30 miles.

Checked: all sensors, all checked okay (even MAF); all vacuum hoses (replaced a few suspect with no improvement); O2 sensor (checked old one and it was working, but put new one in regardless); all relays (working properly); FPR (replaced); intake manifold gaskets (replaced); throttle body gasket (good, no need to replace); injectors (clean, sealed); expansion tank (good, no cracks, solid lines)

In the end, it took the good nature of ScottyWM to let me borrow his MAF and check that one time for sure before plunking down cash on a MAF or DME. It turned out to be the MAF.

Total cost:
O2 sensor, intake gaskets, idle air snorkel hose connector: $77.44
Fuel pressure regulator: $63.09
Used MAF: $85.00

$225.53

Brand new MAF: $300

So I learned a few things...and my O2 sensor, FPR, and intake gaskets are good for another 60k+ miles.

Thanks everyone for their help troubleshooting. Ginger's back in action.