For my CSA 15mm scifi army, i has been searching for some heavy armour to backup my PBI (Poor Bloody Infantry) as i envisioned CSA as heavily tech advanced army i needed some hover or grav vehicles, i look through various sellers as finaly ended at US company named Combat Wombat. the owner of company Scott is very nice guy to deal with, even he write he is to busy( working on something) and it will take some time, he found time and within week and sended my goodies.
Today those beasts arrived in CSA they are Called MGBT Cereberus - heavy grav tanks equipped with Railgun cannon and other defense systems, but enough about CSA lets take a look at model
what i consider as minus there is no turret ring, so you have two option either glue turrets on hull or use magnets. there were also some sanding needed but nothing too serious.
You can check Combat Wombat page for more vehicles, from tracked to grav , some European styled vehicles to more Eastern style vehicles and more. http://www.combatwombatminiatures.com
here is some scale comparsions, on first picture you see UNSC heavy weapons team with Heavy Grav on rest is Allied tanks (Stuart and Sherman with Grav tank)