Just got back from Australia after a semester abroad and I've had this army on the brain. While I was there I drew up some sketches for converted units.
First was a Catachan Storm Trooper - these guys wear full gear and respirators so they can pass through razorthorns and toxic spores even a veteran Catachan warrior couldn't get through unscathed. Instead of dropping from Valkyries like normal deepstriking troops they dig ambush pits and leap from trees, allowing them to appear anywhere.
Second is a Squat Enginseer. When he's not brewing extra stout for the regiment, he smacks around uncooperative machines with his giant hammer and dwarven mechanical know-wotz. Still debating having the servo arm carry a smaller hammer (dwarfs love hammers) or a stein of beer.
Counts-as Seninel t-rex. Catachan carrying a heavy weapon riding a tyrannosaur.
So far I've been mostly taking stock of all the models I ordered and bought and traded for which arrived at my home while I was away. I did get a bit of hobby work done:
Painting is still very much in progress. The crouching guy will have body paint everywhere, representing his squad being forward sentries with cameleoline. The other three, though it's hard to tell here, all have extra pouches and backpacks and scruffy beards. This makes them Catachan veterans, who spend most of their time out in the jungle. The Space Marine will count as Iron Hand Straken and be painted in my brother's Chapter scheme. Lost and left for dead on the planet after fighting off some Tyranids, his broken body was found by the Catachan and nursed back to health. Until contact can be re-established with his Chapter, he makes a fine leader of men and has been gifted with a ridiculously huge shotgun. Also note the Rough Rider and early Storm Trooper.
I should be making a lot of progress on this army in the next few weeks and hope people are interested in seeing how it goes.