New Air Conditioner Question

So we bought our house last year and the AC is 10 years old. It is a 4 or 5 ton running R22.

I've been getting quotes and have narrowed it down to 2.

Company A
14 SEER w/16 SEER condenser Lennox Single Stage $12,440. Company states I must install a 50A breaker per manufacturer spec. Additional cost will be $1-2k.
Warranty: 2 yr labor, 10 yr parts, 20 yr heat xchanger

Company B
16 SEER 5 ton RUUD Single Stage $10k. Owner says it will work on 40A breaker. Separate 3rd party electrician agrees.
Warranty: 1 yr labor, 10 yr parts

I guess my question is which company is right regarding the amperage for the breaker? Given the impending doom of an economy we are in, I'm extremely apprehensive to go into a big expense like this but I'm concerned that the AC will quit on me in the next couple years then God knows what prices will be like as they're inevitably gonna increase. Our summer is already brutal this year.

 

Is the larger breaker suggestion for the outdoor unit, or an electric heat pack in the air handler? Depending on the electric heat pack size sometimes those need pretty large breakers, but if you already have an electric heat pack in your current unit then it’s probably already suitable. It would be helpful to see the nameplate of the unit. This outdoor unit for example lists the minimum circuit ampacity (the minimum amount of amperage the circuit must be able to sustain). It then also lists a max breaker size for the unit. This is only a 2.5 ton condenser though.

 

I haven't seen the new unit so I can't get a label for ya. I'm assuming the Lennox states 50A is necessary.

 

Not sure if this is the correct model line, but either way I think it should work on a 40 amp. Even if it’s a 5 ton the minimum ampacity of the circuit is under 35 amps. A 40 amp covers you for that, so long as your wire is also sized appropriately. They just don’t want larger than a 60 amp breaker installed is what I gather.

 

The electrician stated that the wire is suitable up to 40A but I'd need to go to a bigger gauge with a 50A hence the major increase in cost.

Nevertheless, Company A said they will not be able to install unless I bump up to a 50A.