PWM and MPPT versions of the SunSaver, ProStar, and TriStar can be used in a Positive Ground System. It is important to note that the system can only be grounded in one location.. This grounding point is typically at the battery positive and the solar array output circuit is left ungrounded.
Also, it is important to note that the charge controller UL/IEC62109 certification is only valid for Floating or Negative Ground systems. If this is not a concern for your application then the above mentioned controllers should be suitable for the system.
Please find our white paper on positive grounding linked below for more details:
https://www.morningstarcorp.com/wp-content/uploads/technical-doc-morningstar-positive-ground-en.pdf