BBs are fairly cheap and a decent bike shop will likely have a number of them in stock anyway. Take your bike the your lbs and have a chat, then bring home the right part

This is a good test of a bike shop too. If they sneer and act like they don't care, move on. A good shop will know that although he's only selling a $30 bb for an odd ball build, you'll come back for bar tape and tubes and lube and, one day when you're feeling rich, a new bike. Build that relationship with the easy stuff - my lbs looks after me, is happy to order in odd stuff when available and gives me $10 discount on everything I buy.