The VSDC will save you money and will increase comfort such as humidity
removal by running at real low speed using a Humidistat-Thermostat, but
you Need the 10 yr warranty for the VSDC motor. In your area cooling is
probably your biggest cost so the highest Seer is smart. Ng backup heat
is a good idea.

Electronic air filters cost money to run, and must be kept clean to
filter at their rated efficiency, a good 4" media like the Air bear
seals positivly to the casing, the April Air 2200 Media casing does not.
Get a good large media filter.

If humidity is low in winter April Air has a great unit that is Set
and Forget, it tracks outdoor temps with an outdoor thermometer so it
can be set to never overhumidify you, which leads to water damage and
mold. With continual increasing utility prices put in the highest
efficiency equipment if you can afford.

Be sure a load calculation is done in writing and you get a copy,
oversizing is a common issue and leads to higher humidity, less comfort.
in summer.

The installer is the most important part, pick one with a good
reputation that you think will do the best, the cheapest price means
nothing if a hack uses the wrong equipment and oversizes you. A good
installer will check your ducts for proper sizing, If everything is not
sized right you will never acheive rated efficiencies or maximum
comfort.