Type of lift? It depends on the type of work you think you will be doing most.
If you will be doing a lot of brake jobs and work that requires tire removal, a 2-post lift is obviously the best. Not only are you able to quickly get the car up in the air and remove the wheels for whatever type of work you will be doing, but you also don't have the ramps in the way while you are working. I can't tell you how many times I've been ticked at myself for having to try to reach at something in a weird way or had a hard time getting a breaker bar in place because the ramps are in the way.
There are a couple kinds of 2-post lifts - Symmetric and Asymmetric. They both work about the same, but the symetric is designed to lift the car with the lift columns near the center of the car, while an asymmetric is designed to put the columns near the front door hing, even though the car will then have more weight hanging off the back. Asymmetric styles are build differently so they can handle the added stress, and are therefore more expensive.
For all lifts, but especially for 2-post lifts, you must have at least a 4" thick concrete floor of 3000PSI concrete. 2-post lifts must be bolted to the floor. Some 2-post lifts have the cross-post hydraulics in a pipe across the bottom between the posts, while others have it across the top. Either works fine, although if you have a 14' ceiling and you have a 12' top-bar 2-post system, you will be limited to lifting to only 12 feet regardless of inside ceiling height.
4 Posts are much easier to install and manage - technically you really don't even need to bolt them to the floor (although they are more stable if you do). For oil changes and work through the center of the car (transmission work, etc) they are great. Most also come with a "jack tray" which is a specially reinforced recessed tray between the ramps, strong enough to put on one or two bottle jacks. YOu can use these to lift the car off the ramps to do tire changes, etc - but it takes time. More importantly, because the jack tray is through the middle, it may be hard to find a safe jacking point - most cars have their jack mount points along the outer rails, but the 4-posts' ramps will be in the way of using these.
You can get something called a "Bridge Jack" the fits in the jack tray and has extendable arms so it can place contact points under the correct lift points. These are usually pretty expensive though, but you can get most of the same functionality as a 2-post lift with a pair of bridge jacks added to your 4-post lift.
4-post lifts are also nice because they are ideal for car storage. With a set of drip trays underneath, you can stack 2 cars easily, whether for the night so you can keep customers' cars inside, or for longer term storage of a special project car.
The biggest brand is probably Rotary - I'd say 80% of commercial shops have a Rotary lift of some sort. Here in the Northeast, Mohawks are common as well.
For my own home use, I have a 4-post that I bought from American Automotive - http://www.americanautomotiveequipment.c...000xlt.htm
It's a cheap Chinese Steel unit, like the majority of the low cost lifts out there - but it was well made and the hydraulics and pulley system are well designed.
In all cases, look to get the 220/240 volt version of whatever you buy. Make sure you get a Single Phase motor, not a 3-phase motor. 3 phase power requires a special connection and service from the power company and if you don't have it already, you don't want to pay to have it put in.