I was reading an LP here (http://lparchive.org/UFO-Aftershock/Update%2005/) for pointers on how to manage my tracks and I noticed that the armor looks different in the screenshots. That can't be vanilla right?

That would be the Combo-Mod you can find over at Strategy Core, be aware that this mod adds new enemies and stuff and will make some missions harder to do.

Is the combo mod a good mod for Aftershock? I just finished Aftermath so I'm wondering if I should continue with that mod.

If you need a mod (for me vanilia Aftershock is already good enough) then I think the ACM mod is the better.
Combo mod is old, and Consequence mod has been ended bad by its modder (but in first versions it was my prefered).
http://www.strategycore.co.uk/forums/topic/7314-acm-ufo-aftershock/