I've had one Super Blackhawk converted and bought two used Rugers that were converted.
If you do send the gun to Ruger, remove your original parts, as they sometimes get "lost.'
If you must
have a transfer bar Ruger, buy a new model and sell your old model. An unconverted old model or a New Model is preferable to a converted old model, believe me. What you get back is an action better suited for a gorilla's use.
As far as sights are concerned, any gunsmith usually will have a Ruger front sight of correct height. Rear sights can be had from Gary Reeder, Hamilton Bowen or Dave Clements.
This is Gary Reeder's rear sight on my .45 Blackhawk:
It is all steel, and is superior to the factory rear sight.