Our local W-M seems to have the Motorcraft filters in stock. I also buy the FL820S for my 95 CV. From some of the info that I've seen here though, might be time to stock up on the FL820S next time I'm in there. The ST-2's also seem to be in stock when I look, but I usually stick to the Motorcraft filters.
On thing that is more hit and miss is the MC 5W-30 sythetic blend, though. They only carry it in the quart bottles and it's been sold out on more than one occasion.