Unless you know for sure that the wood studs are securely attached to the concrete, you should plan on anchoring into the concrete. This usually means using a hammer drill and expansion anchors. It's an intermediate level home handyman job. If you're not comfortable, find a friend who will work for beer to do it for you. The anchors will need to be long enough to go through the 1/2" drywall and 1-1/2" cavity and at least 3-4" into the concrete wall.
If the studs are well anchored, you could fasten to them with 2" lag bolts. If you use 4 bolts, each one is only taking 50-60 lbs of load.
Have you considered a surface mounted
wiremold as an option to chopping out drywall and insulation? You can paint it to match the wall if necessary.
