How hard is it to find an oil cooler for these bikes? Is it going to be beneficial to put one on a stock motor or do I not need to worry about it? Are there any bikes that I can pull an oil cooler off and it will go on the 500? Where can I find an oil cooler? There is one on Ebay I am thinking about getting right now but if its not going to help my bike at all then I wont.
It's easy to find an oil cooler. It's harder to find one with the required thermostat/bypass valve included. If not, it will likely over-cool the oil more often the have it get to the proper operating temperature.
If you have an oil cooler and the oil never gets to a temperature that opens the bypass valve, the oil stagnates and any condensation in the oil begins to form amino acids hungry for bits of metal to eat. The valve also makes complete oil changes a bit of a challenge, unless you drain the cooler in a separate operation.
Don't get an oil cooler with the expectations of cooling the engine. It's an oil cooler, not an engine cooler. If your oil is wearing out faster than you think it should with heavy use and power loadings, then you might extend the oil quality a bit longer with one attached.
Also consider where the oil cooler dumps it heat. Does it do this right in the airflow path of the engine's primary cooling system, that being the fins on the head?
How about this? Since you just want it for looks, go ahead and mount it out front and run the lines down to a fitting JB welded to the engine case. That way you get the looks you crave with out all the hassles associated with it.