I just installed two new Carrier AC units with the heat strip option. You can do the heat strip option yourself as long as the inside ceiling unit is the heat/cool model. If the inside unit is not a heat/cool model then you will have to replace the inside ceiling unit with the heat/cool model. If you have the heat/cool model it is a simple install of the heating unit, two sheet metal screws and plug the unit in and you are done. If you have to replace the inside unit it is a little more involved, removing the old ceiling unit and installing a new one, but if you are inclined to do the work yourself it isn't difficult. Ceiling assembly with the heat strip option is about $120. Just the heat strip option for the heat/cool ceiling assembly is about $100.
2004 Holiday Rambler Presidential 5th Wheel 30SCD