What is the best sound to put into these engines (Spectrum SD45 and Spectrum 2-10-2) and where is the cheapest place to get them? I'm new to model railroading and need some help adding sound to these engines.
For best sound, I recommend Soundtraxx Tsunami. When using the TSU-1000 series, available space must be considered.
Check this page for dimensions.
http://www.soundtraxx.com/dsd/tsunami/index.php?p=1000.php
For SD45,
http://www.caboosehobbies.com/catalog/product_info.php?manufacturers_id=1039&products_id=85831
For 2-10-2,
http://www.caboosehobbies.com/catalog/product_info.php?manufacturers_id=1039&products_id=48657
You will also need adapter harnesses from JST 9 pin female to NMRA 8 pin male, oval speaker with snap-on enclosure for the diesel, speaker for 2-10-2 depends on your choice of mounting.
Regards