They look kinda big for my liking. Can you not just take off the clip-on. keep the stock bar end and pour in your lead from the opposite end? Cap back on, re-assemble, can't even be seen......... just a thought.
I've found that gloves can also make a big difference
Changing the angle of the levers will also improve the situation. Numbness is probably due to the fact that you're placing too luch weight on the palm of your hand. If you lower the levers you'll get less pressure on your palms.
Other solution would be to not ride so upright ;-)