Lennox ML180UH vs Armstrong A80UH

First time posting here, so mea culpas where necessary...

Anyway, my 40 year old Rheem in my attic died (heat exchanger is done) and I've shopped around a bit and the contracter I'm probably gonna go with gave me 4 options, 2 of which seem realistic. The other 2 are 2 stage units which the contractor feels is unnecessary for the relatively small space.

For context, this is for a ~800 sq. ft. space, upper level of a duplex. Running heat up from the basement isn't practical for multiple reasons.

The two units offered are a Lennox ML180UH045E36A or an Armstrong A80UH1E045A12, $5600 vs. $5200 respectively, all in parts labor etc.

The price is close enough that I'm not really hell bent on saving $400 if the Lennox has any kind of measurable advantage whatsoever. Any thoughts? Any more details needed?