I am wanting to convert my N scale turntable to DCC.  I can not find the decoder needed anywhere.  Instructions say I need either Bachmann  item # 44915 or item # 44926.  I can't find these decoders.  I just want to go from DC to DCC on my turntable. 
Thank you for any help.

Hello
Brand new here, first post.  I currently have an n scale turn table that I run on DC power. I presently have the power pack and speed controller system.  I only use this controller to operate the turn table.
I use an MRC tech 6 to operate my DC locomotives. I was thinking of going to DCC and would like to convert the turn table to DCC.  I know I have to install a decoder, Bachmann says #44915 is the decoder to get, however I can't find that anywhere?  Also do I need to get the E-Z command plus system to operate the turn table once I find the decoder?  I appreciate any help from the group.  As I said I am a beginner, so the simpler explanation is appreciated.
Thanks in advance.
Mark