I use a fillet knife as well for most of the butchering.. We also have a long butchering knife for cutting steaks but otherwise for all other butchering, any knife will do and I prefer my fillet knife.
My fillet knife is from
www.grohmannknives.comthey also sell butchering specific knives.. Never used a 'boning knife' but I am sure it would be perfect for the job..
Cheers.