Should I upgrade my evaporator coil when a I get a new furnace?
You need about 1 ton of cooling per 400 sq/ft.
At 1,400 square feet you will be undersized by about 1.5 tons. If you have excellent insulation everywhere then 2 tons might work but you will likely notice that your unit is constantly working on high for hours on end.
Also, from https://www.cooltoday.com/blog/is-it-bad-if-my-evaporator-coils-and-condenser-coils-dont-match

For example, an evaporator coil that is smaller than the condenser coils might, in some cases, provide better dehumidification but it can’t cool the home as well. On the other hand, an evaporator coil that’s larger than the condenser coils will cool the home well but will remove little to no moisture from the air.