to replace A/C or not?

[Gabe E.]

Hi BP community. Here in south Texas an A/C/heater is needed basically year round. That being said my current unit 13 SEER (Goodman) being over 15 years old has a blower that has gone out. This unit is rusted out, has had leaks in the past. Installed by previous homeowner. This will cost about $400 to replace in addition to $350 ive already spent earlier this year to keep in going. I plan to rent this property by early march of next year. 

Ive gotten about 4 replacement quotes ranging from $4775 to $7k, the less expensive 2 being as follows:

Repair vendor 1: Install a 3 ton 16 SEER PAYNE system, 10yr wty for $4775. Less a $375 energy efficient rebate. This vendor was referred to me by my trusted electrician. This vendor is the owner of a very small AC company. No reviews online found of this company good or bad. The more i read about this model PAYNE the more i see it as a 2/5 star system with LOTS of problems down the road. Although the vendor seems genuine to stand by his work. It is a new unit and the vendor/owner seems very experienced.

Repair vendor 2: Install a 3 ton 16 SEER LENNOX system, 10 yr wty (free maintenance checkup twice/yr). This vendor is a bigger company but has rave reviews for workmanship online. This brand also has rave reviews online as well. Same energy efficient rebate. $5,500 installed.

So with 2 new different brand systems and vendors, is it recommended to pay the extra $725 for vendor 2? Or do we keep the costs down and keep vendor 1 hoping the new unit doesnt cause problems later on? OR should i just keep repairing the old unit and cross my fingers?? Are these prices still too high? Im trying to keep costs down but am on the fence on this one, never replaced anything this expensive on properties... what have other investor thought processes been?