The snotlings from WFB make great minis for BB.
IF you get a good pack of them. I ordered 15 packs of these guys to put into BBFigs.com and I'd say only about 50% are easy conversions to be BB playes. Some packs I'd be lucky if it was 25% that were good. Its why BBFigs.com doesn't carry the WFB Snotlings ... the mix of easy conversions to not easy in the packs was just too much on the not easy side in too many packs. Since those packs are entirely random ... you can get lucky and get a great pack for BB. But my recommendation would be to purchase two packs to try to get 8-10 nice different Snotlings for conversions.
I am liking these figures
http://www.impactminiatures.com/index.php?option=philphigs_profile&id=PP_IMP1. I think the Imps would work ok for the snotlings.
Sir Thom
Those figures are definitely Snotling sized.