depends on how thick your wallet is and ambition level
Btu's are no different Honda versus aftermarket heater core
I put a couple summit racing heater core\fan\duct kits in rzrs over the years .... way cheaper by about 75% but needs a little figuring for parts... I think for about $150 we were all in for heater core, y fittings, defrost\heater duct. We did tie in after the thermostat up at the radiator so you had to wait for stat to open for cab heat.