I'm not sure if there are any health pickups. I always buy mine from the Ammunations.
There are lots, some are hidden in garages and interiors. Very convinient if you need to drawback from a fight.
MB made his map out from the scm information - check this thread: http://forum.mtavc.com/viewtopic.php?t=8949
I would do the SSV map and Staunton if I knew how
actually...i didn't make the map out of the scm, i used to scm to check if really all pickups were on the map, i prety much found all of them myself