Irken Rising

It's got chicken legs! I'm gonna eat you!

The Cygnar minis have been sold, and (hopefully) soon I shall have enough money to assemble my mighty Irken invasion force! I have (of course) located my Irken soldiers, I have found my SIR Units (Hydra Miniatures' Minibots with a head resculpt), and I have even found my Megadoomers (Hasslefree's Grymm Walker to the right). A little tweaking will be in order for all above, and they will not quite look the same as their cartoon counterpart, I will strive to get as close as possible.  A rocket pod added here, a gun repositioned there, and voila! The Megadoomer Mk. II Combat Mech!!!

But then I am confounded. I need a Riptide stand-in. I need something to represent my Crisis suits.

My first concern is the Riptide. I have a plan here. I'm thinking of using a decent sized Zaku model. It has to be big enough to fill a GW oval base convincingly, so I'm thinking 1/100 scale, but that might be too big. I'm pretty sure 1/144 will be too small though. Another model altogether would be preferred, but what to match this?

You! Twist some knobs! And you! Pull some levers!

I'm also hung up on what I should use as my Crisis Suits. Since they're pretty agile I was thinking some sort of hovering machine, sort of like these, but I'm not sure. Irken technology tends to be rather bulky. Again, I continue pondering.

Since this "invasion" takes place some time after the events in the series (yeah, we'll say that) the vehicles can look a bit different, but I don't want things to be too radically so. I posted the question on a couple of forums looking for help, so hopefully I'll get a response soon. If not, however, my friends have been quite helpful in finding minis thus far, so here's hoping, right?