A sub bass is very simple to design with pretty much any synth or sampler. You didn't really describe what you want very well, but it sounds like you just want a one shot. But basically I'm saying, it's so easy to do yourself that you just should learn. Google or any decent search engine will help you. Or you could chop one of the hits from this loop, put a sustain loop point in there, and then you will be able to play or sequence whatever you want from the sample.