Lenny,
On the Heartbreaker, use the Love channel in Hi Gain Mod and Twiddle from there. If I remember correctly, the manual has the setting for a Santana-esque Mark I sound. I'm skeptical that you'll be able to get it out of a LSS. I have owned the Heartbreaker, LSS, and the Roadster. All three are great amps in their own right, but the Heartbreaker is where you should be the happiest. The Roadster's recto tone heritage will prove frustrating trying to get MKI sounds. Just my two cents and YMMV. Good luck!
Matt