I need to know what kind of real end oil should i use on my 2007 yamaha vstar classic 650

For the final drive oil you can use any 80/90 Hypoid gear oil. If you choose a synthetic Hypoid gear oil your rear end will run cooler. One quart of oil is enough for 4 or 5 rear end oil changes. Because the rear ends are so expensive (around $1000), I change my rear end oil every other engine oil change.