M1A2 SEP project

Cant answer you questions but apparently Fruilmodel is coming out with MI tracks soon, there looking for references on their website.

I don't know what color corresponds in the Vallejo line, but Testors Model Master Sand, FS33531, is a near match out of the bottle to modern CARC MiddleStone (Sand). 

As to storage, I don't use specific sets, but just put together what I want from various sets.  If you are looking, the Legends Productions M1A1 set is full of great pieces.

As to PE, I don't think either the Dragon AIM or SEP need any more PE than what is in the kit already.  Both PE sets included are quite extensive.

Here is my M1A2 SEP TUSK w/full interior that I completed recently.  I used the Model Master Sand on it. 

Good luck on it and post some pics here once you get started on it.

Go over to the group builds. We have a M1 Abrams group build going on now and there are several different models being build now.  It might be on page 2 or 3 by now.

Check out Real Model. They might have something you need. Their stowage sets always look good and realistic too.