Well what is a good and affordable brand? I have a friend that can get a unit at cost who is a big contractor would it be cheaper to buy it that way and pay some one to install it? And what are the specs needed on a three ton unit? Thanks

No one around here will install a unit you already have. So inless you have someone that is able to install it I dought you will get it done that way. But I could be wrong. Depends on what area you are in I guess.

There is a certain brand that I highly favor... based on 19+ years of field service experience... I even put one in my home... take a peek to the left... you might have success in securing a capable installer by posting an ad on Craig's List in your area... if you decide to purchase the equipment from your acquaintance...