Mikuni flat slide carburetors are the E ticket on a Harley. Easy to tune and they come in a lot of different bores. Dellortos are cool but not that much fun to deal with. Parts are not easy to come by either. Having owned a number of motorcycles that use them I'm not really crazy about them at all.
(Unfortunately)I have small fortune worth in Dellorto SS1's sitting on a display shelf in my garage. These are "new" having been completely restored and rebuilt by the Dellorto specialists in the UK. They are gold to the vintage motorcycle racing crowd and they are a bear to get parts for and when you do be ready for a shock. I recently heard of 1 carb body, 1 complete carb and a parts carb going for $600 at a swap meet and the buyer was very happy to pay.
Here's the Mikuni link:
http://www.mikuni.com/fs-products_guides.html
