been there, done that.
what's your target customer base...have you done any research on what they want?
for some smaller brands you'll be able to go directly to the company and setup an account and discount level, for larger companies like bilstein they want minimum of 30+g's for a stocking order to be a wholesaler which may not be something you're interested in right off the bat, so you would have to go thru one of their dealers who will discount you.
Are you servicing cars or bikes?
Good luck with your business!
A good friend is also doing the same. As asked before,who is your target market ?
IF you are going to service the kinds of bikes you ride then just think of who it is you buy from or who they get their parts from and once you have an address for a shop most will be willing to sell wholesale to you. If the distributor is fairly close you can get items shipped ups overnight, my local offroad shop does this all the time for his customers and does' not charge for it.