I've wanted to field a brood of biovores for a while now, but the model (beyond being stupid looking) is insanely overpriced. At $50 a piece, fielding a brood of three would cost prohibitive. Thankfully, while trolling the boards over at the tyranid hive (howdy, boys!), I came across a great thread where users share their conversions. Among them was the brilliant idea to use the new hive guard / tyrant guard kit to create "counts as" for the biovore.
Having purchased and created a set of two tyrant guard, I used the leftover model to create the first of my new brood. I've attached the bio-weapon to the creature's back, and re-purposed the armor plating to bulk it up. I've starting filling out the joints with greenstuff, and will add some extra tubes as well.