Here are the light armour support that, if necessary, drop with the infantry. As you can see I've used wire mesh as an armoured crew compartment, representing them protecting themselves from above in urban combat zones.
Comms are florist wire. I drilled holes into the tank and simply glued the wires in. Quick, cheap (free!) and very effective! (also durable) These sentinels have a long history of fighting Hormagaunts. They handily hold them up for quite some time, maybe even killing one or two. Keeps them away from my men anyway!
Next up is the heavy support in the form of the ubiquitous Leman Russ
And from the other angle... (excuse the terrible lighting please!) Note the loud-hailer on the turret. A clap on the back for anyone who guesses where I got that idea from!
The track guards are the bottom sections from the Chimera chassis and the old launch-box from the old hunter-killer missile chopped up and folded out (this Russ was bought before the new accessory sprue).