What developer to use with HP5+?

I've been using HC-110 with dilution B for a while and it doesn't give me the contrast I'm looking for with the HP5+. I've been using same timing as suggested from the Kodak info sheet. I understand if I shoot stuff that are more contrasty, I'll get better contrast. I know that if I leave it in longer/shorter, it will just push/pull the film.

However, does anyone have any idea which developer or dilution will give more contrast with HP5+? Also, since I don't develop film too regularly (2-3 rolls per month), I'm looking for something that can sit on the shelf for a while too.