I would advise against a heel/toe shifter. I had an '85 Goldwing, which came with floorboards and a heel/toe shifter. It was awful. It felt clumsy and awkward. At first I thought it was stock, and I was stuck with a bike that was no fun to ride. I quickly found out on the GW forums that it was not stock, so I ditched the floorboards and heel toe shifter, and got a stock shifter and pegs from eBay. WOW! What a difference. Suddenly the bike felt 300 pounds lighter, handled a lot better, and became fun to ride.
I also had a '95 Goldwing 1500 with the same issue. I put it back to stock, but the heel/toe shifter had already done it's damage. About 15,000 miles after buying it, it started jumping out of 4th gear under hard acceleration. Apparently the shift mechanism was not very robust, and the previous owner had the habit of riding with his foot on the shifter. This preloaded the shifter, and eventually wore something down inside the engine. I don't know if that applies to the Enfield or not, but it turned out to be a very common problem with the 1500 Goldwing. A high percentage of those with heel/toe shifters had transmission failures around 60,000 miles. After that experience, I decided never to buy any used bike with a heel/toe shifter.