I think Cakewalk did one as part of a pack with drums, keys, bass, and strings...cakewalk studio instruments it was called, around 50 euros. Not sure if it was 64bit, and only the bass and strings were any good.
Another avenue would be to use JBridge to allow your 64bit DAW to host 32 bit plugs...then you could try Broomstick Bass, around the same price as above but way more tone options.