Was there any specifig brand/seer rating restriction with the GHGrant?

It's more complicated than that. The major components of the system all have to be qualified for the rebate, down to the component model numbers. There's a lookup tool to see which model numbers qualify. For a hybrid setup like mine, there are three parts:

• Outside model number: this is the actual heat pump component that gets installed outside
• Inside model number: this is the condenser coil that gets installed on top of the furnace
• Furnace model number: this is the model number of the furnace itself

A ductless system would only have two part numbers involved, the outside heat pump unit and the inside wall unit (though a ductless install can have multiple inside units in multiple rooms). No furnace for a ductless system of course. Edit to add: and all of the major components you get have to be certified with each other by the GH program. They don't want you mixing and matching.

Every HVAC company I talked to was pretty knowledgeable about the GH program, so if you tell them you're an applicant then they should put together a quote that qualifies. Multiple HVAC reps advised me to make sure that all rebate-covered part numbers were listed clearly on the invoice. Apparently if that info is missing it can derail the rebate until the invoice is updated with full info.