yes, because we are THIS close to banning Tom's DC engines from the layout
I'd agree about the LokSound. Specifically you'd need the XL version, either 3.5 or 4.0, depending on who you can get it from.
I'll be putting an XL into my Sunset GG1, to control both motors and give me GG1 sound sets.
To answer your original question, for a Tsunami use heavy steam for the M1.
The medium is for something like an Atlantic, the light for a A or B series shunter.