I picked up 6 floating aliens from Troll Forged that I am going to be using as Zoanthropes.
I think they are pretty nice resin models. They only had a small amount of clean up and the two types of posable heads make it easy to have different squads too.
The basing material is just the insides of Lotus seed pods which are proving to be tremendously versatile!
More about Mike's Tyranids can be found on http://nidomnom.blogspot.ie/