The Gigbar 2 and Gigbar Move are both perfectly acceptable as starter lighting pieces.
One of my biggest issues on those all-in-ones is the lasers. I just don't believe cheap spot lasers should be used at high end events. But I believe they can be turned off. So just be aware of that, if you get into doing weddings, crappy lasers are a big no-no.
It partially depends on what kind of events you see yourself doing, but if I were in your shoes right now... Rather than buy a gigbar, I'd buy something like the Chauvet DJ Wash FX Hex.
1) You're going to come in at like $280 rather than $600-$900 for the bars.
2) You get lots of light from a single fixture, so you're going to be able to wash a fairly large area in color.
3) The built in programs give you plenty of eye candy effects out of the box that you don't really need to add the cheap movers or derby lights to it.
4) If/when you expand, you can easily add more of these or other quality fixtures to your rig and these won't look out of place. Where on the gigbar... you can probably expand to 2 of them, but if you're moving upmarket I don't think that's what you'll want.
So basically, cheaper now, greater future options, and still plenty of light to say you offer dance floor lighting.
Uplighting... I'd price check rentals in your area. You can literally start by offering it to clients at your cost or maybe with a slight markup. Don't buy your own set until you have created some demand for it.