SP Engine rebuild project

I actually have a new SP Engine rebuild project. I acquired 2 IHC pseudo SP M-4's for $19.95 each. I had thought about using the cylinders for a Bachmann C-9 rebuild.  However an M-4 or M-6 are more appropriate for my current SP modeling passion, the San Ramon Branch.  Time to work on these in 2019 while waiting for Intermountain 70 Ton covered hopper kits to show up. 

Any thoughts about re-motoring and DCC upgrade are welcome. I have a lot to do on this engine. I need to locate an MDC shorty Vanderbilt tender for one of the M-4's.  I plan to scratch a whale back tender too and may do that first to house the decoder.

I have ordered a Bachmann "shorty" Vanderbilt tender from Bachmann Parts that appears to resemble the short tenders M-4's had. It cost as much as the two IHC engines combined.  And now I need a new decoder as I have none in stock at home. This is rapidly getting to be an expensive project.  Well my other pre-orders are not looking like they will arrive in the near future.