If you have the Limited series, I believe you already have a Novak style sight from the factory. You should be able to get any other style of Novak " "lo-mount" sights to slide right into the dovetail. They have two-dot, bar, and nite-sight styles. Have you checked http://www.brownells.com ?
Any good smith should be able to mill your slide if you wanted to go to a Bomar style cut, as well.
Any good smith should be able to mill your slide if you wanted to go to a Bomar style cut, as well.