Is there a combination of ez-track that I can use to form a 24 inch radius curve for the cormers of my layout.

I would like to convert my DC GP-40 to DCC operation.  Can I just purchase the printed circuit board from the parts list.  Also, do I have to change the motor to the one with the resistors attached or can I keep the origional motor.  All help welwome Thanks

I have just restarted  getting into model railroading after about 40 years.  I purchased a couple of starter sets of Bachmann trains and am now expanding my layout and purchaseing more rolling stock.  I got some of the silver series cars and found they roll better with the metal wheeled trucks.  I would like to put these trucks on my starter set cars but cannot find them in the Bachmann parts catalog or web sight.  Do the Kdee trucks fit the Bachmann cars.  Need all the help I can get. Thanks Trif