You got a few options:
1. Find the ooold ones on ebay or similar seller. If you're lucky.
2. Buy a lot of Hellscannon crewmen, if the online site will still let you. You have to convert weapons and only 3 base models, but not too much to do.
3. Buy the big-hat Blood Bowl CDs and add weapons.
4. Convert your own, using Dwarf and Maruader parts, using Green stuff. PLENTY of different guides on http://www.chaosdwarf.com/cd2/.