Air Conditioning - Unmatched system

Have an all electric house with 3 ton A/C, heat pump system, all one year old. Both inside and outside units are 3 ton. Have been told by other A/C installers that proper size for our house should have been 3 1/2 ton units. Builder's installer gave us wrong recommendation. In order to keep our cost down which route would be the best. Upgrade the outside A/C unit to 3 1/2 ton or upgrade the inside unit to 3 1/2 ton? We need more cooling. Upon checking I find some houses in neighborhood are matched systems,but there are some houses that have larger outside than inside units, and also some are vice versa. Heating in winter is fine, and no problem with humidity with current unit combination. Original installer refuses to work with us anymore.

Dont in any way kick up the outside unit. it dont work that way are that good. I know we have put bigger blower coils on some heat pumps and they work just fine. If you have the $$$ for a new blower coil look into a V/S blower on it. They are great.

ED;)

When you say new "blower coil with Variable speed fan" do you mean upgrade the whole inside air handler to 3 1/2 ton or is this blower coil and V/S fan just one part of the inside unit?

Yes If you want to do this then change the whole inside unit. The coil will be bigger and need the bigger blower case for it.

ED;)