Insulating a basement floor

churchlady

I looked for this topic in other threads but couldn't find anything...
I'm hoping to get a bit of guidance/advice before we get into insulating a very cold (& ugly) basement floor.
I want to lose as little headroom as possible, so am hoping to go with either 1/2" or 1" foam on the floor with strapping (lathe?) @ 16". What info I have read suggests using treated wood, but am at a loss at what to use as the only treated I've seen around is 2X (1 1/2"). Maybe this is a dumb question but here goes: Is there such a thing as treated plywood? If I could have a sheet ripped down to 2" wide strips couldn't that work as the nailing strip that would be attached to the floor between each foam board? Or is the only solution ripping 2 X's down to the right depth?
PS: Yes, a vapour/moisture barrier will be put down first!
I look forward to any input here, thanks.