So I have had all the locals out to give me advice and proposals. They all agreed on some bigger points which helped.
Based on referals and reputation I picked the installer. Their main brand is Carrier.
Background: 3400 sf, 2 story home near Philly, PA built in 1998. System was put in by builder: bryant. No major issues yet however outside unit is making some noises (clunking when turning off and on)
Current gas furnace is 90%
Looking at 3 options:
single stage 59SP5 furnace (96.5%)
2 stage 24ACB AC (16seer)
two stage 59tp5 furnace (still 96.5%)
2 stage 24ACB AC
a few hundred more $
two stage 59TP5 furnace
25HNB6 heat pump (up to 17.2seer)
about 12% more $
My head is spinning... I think they all seem fine.