The differences between boas and pythons are really irrelevant to being kept as pets, as both come in a variety of different sizes, shapes, temperaments, colours, etc.
If you are looking for something small that is pretty tolerant of handling I would suggest a Spotted Python, Children's Python, Rosy Boa, or Sand Boa. They are all easy to care for and don't get easily stressed out from handling. Ball Pythons can be another choice, but only if you can deal with their fasting and sometimes finicky eating habits. They do stress quite easily, and the fact that they are often quite still while being held isn't an expression of being comfortable, but rather being defensive. Some smaller Boa constrictors can also be a good choice. There are quite a few that stay under 6' in length and are typically good feeders and quite hardy. A male Brazilian or Colombian Rainbow Boa might also be a good choice. Although they are quite strong for their size, they are typically easy to calm down and are excellent feeders. However, they are quite sensitive to their humidity requirements, but given the correct enclosure, are very easy to maintain.