Is not the bio-wheel a patented product of Marineland Inc.? they are esssentially the only one with this specific product.
Eclipse, Penguin, Emperor, Magnum & BIO-Wheel PRO are all Marineland products. I hear there are kits to adapt many HOBs to fit a BioWheel. Aqua-Tech has a bio mesh that sits in the water (poor o2), but you can put a bio-wheel into it.
IMHO Bio-Wheels are an excellent HOB solution (alternative) to wet/dry.
i agree that HOB with biowheel are really great... i had a 29 gal eclipse tank with 12 goldfish sized 3-4 inches plus corydoras and plecos. barebottom and the biowheel just handled it right.