I don't think we can really answer that for you. You've done different classes before, but only up to 20 according to your first post. A lot of people will tell you, myself included, that you should start with as few different classes as possible. Tank +4 Shammies is always a popular starter group because you only have to figure out 3 specs {tank, healer, 3 same DPS} while you're also trying to figure out how to deal with the basic mechanics of 5-boxing.

That said, I didn't follow my own advice. I went through about 3 or 4 fully mixed teams before I ever rolled "clones" because I like to make things as complicated as possible, lol. If you're up for the research to learn all the classes and all the work involved in setting them up, then you should be ok with just about any spec/class. Though I would advise against cat druid, rogue and possibly monks to start with - their resource usage isn't so easy-mode to work with for a new boxer. Ditto with melee teams. I adore my melee team, but you need a firm handle on the mechanics of multiboxing and the micromanagement involved before you get into the quirky nature of Melee.

The group you picked will work, there's nothing wrong or terribly difficult about any of their mechanics, though {depending on spec} they all do have ground-target abilities that you're going to have to either learn to use or sacrifice the DPS for simplicity's sake.