The top of the line A/C/heating systems are Carrier, Lennox, and even Heil is starting to impress me. These 3 come with a 5 year parts warranty, as do others due to factory improvements and a "we back our product" attitude......This is good. Every Service Tech can tell you the pro's and con's of any brand of equipment, but do your own research, you'll learn alot.
As to the type,.......All are good, but have different cost's of installation and operation. Heat pumps are o.k. for areas which see temps of 34-40* but no lower. Any lower, the efficiency is gone. At this point your system will ghange over to it's supplemental heat source,.gas/electric. You also have to look at the cost of gas (vs) Electric? which is cheaper?
Package Units are nice because they alow for all repair and maintenance work to be done at the unit. Everything about this unit is right in front of the service tech. No need to track through your house. With straight A/C and gas heat, this is a goog choice, but may be more expensive.
Split System.... Also OK, but requires 2 major pieces of equipment.
All Types are widly used in the industry and can make your living more comfortable. The big Question is,...What's best for you? A contractor can help you decide....
Sorry I dragged on and on....
Hope this was of some help to you.