Perhaps you can now buy off-the-shelf LED replacements that fit in the RK lamp holders. But a few years back I ended up assembling my own LED replacement for the lock-on (sideways facing light):
and the lever controllers (upward facing light).
I do NOT wish this task on anyone! Do NOT try this at home! 
Separately. As for powering turnouts from Accessory power, I'd think this was the more common method (rather than using track voltage)? Sure, you can't beat the convenience of using track voltage with the screw-terminal jumper...but I wouldn't call the Accessory power method a "ton of wires." Whether you run an Accessory "Bus" alongside the track picking-off the voltage as needed...or just a few point-to-point wires from transformer-to-switch depends on how many switches you have, if there are other Accessories to be powered, etc..
