I agree with Madbrush if when you say bar fridge you mean the kind that fit under a counter 3ft x 2ft, it will not be able to keep up, if it takes more than 5 minutes to fill your tank it will burnout in no time. If your compressor can fill your reservoir to 100 psi under 2 minutes it should have no problem with heating (if your reservoir is not too small, which would loose it's pressure too quickly, so as to need to be refiled sooner). Your compressor should be able to rest a bit between fills.
Like JTairbrush said, on a fridge you have all the components you need to turn on and off the motor (that is the relay switch in which the thermostat connects to, to signal to the compressor to start, you just need to connect the pressure switch where the thermostat was connected).
For the oil since it is no longer used for refrigeration it does not need refrigerator oil (sorry JT), refrigerator oil is actually very smelly (The one that was in mine was) It can be replaced safely with mineral oil you buy at the pharmacy (which smells nothing). To drain the motor, you will have to turn it upside down, and the oil will come out of the intake ports (where the air is sucked in the motor), be careful because there are usually two of them. Make sure to collect it in a container so you can measure how much oil was in there so you can put the same amount back in. Putting the oil back is not to hard you just need to connect a hose to one of the intake lines and place the other end in the container containing the correct amount of new oil it should suck it up, you can block the other intake line with your finger so it goes faster. If it does not start sucking the oil after a few seconds make sure that everything is connected correctly, you don't want to run the motor too long without oil.
Here is a link to a video of someone who replaces the motor of his compressor with a fridge motor:
DIY Silent Compressor
You can find lots of info on this site. Hope it helps