you should also consider the width of the bars, the handlebar and raiser fit, you should try a couple of bikes to be able to select the differences then selecting the best one.
seats selection is very critical, you need to select seat that is very comfortable, especially if you go on long trips, there is a variety of accessory seats in the market, you can ask some friends or try riding with them for a long trip to select a perfect one, however you start with the original bike seat and then see what makes it comfortable and what doesn't then search for a one which is better.
The foot pegs are also important, some models don't have foot pegs and some have an uncomfortable ones. you can find a lot of accessory foot pegs in the market, the wider ones are more comfortable and if they have a rubber insets they can keep your feet a little more vibration isolated.
As these main areas are covered, you may need to consider long term finances like insurance, repair, parts and accessories costs. make sure you test the bike before you buy it. choose on passion as a bike that makes it throw the whole check list may not excite you and you might even stop riding if you don't like it and don't/can't purchase a new one.
Make sure you wear a helmet when driving, you might want to purchase the helmet after buying the bike to find a one that matches.
