I looked around for a bit (newegg, xoxide, plain google), there doesn't seem to be much 70mm fans around, and none of them are LED's. Maybe someone else could find it. As for 3 pin connector, you can just get an adaptor for that.
Yeah adapters are only $4 at compusa (if you can't wait for Newegg). Ive only seen 80mm LED fans (i have 3 blue ones). Are you sure you can't put an 80mm in there?