Well, I think size matters, but I also recommend maybe spreading it out a bit too.
First, I have almost entirely ADJ lights, and am pleased with them. I also have 8 mega Bar 50's and 4 Mega Panels. I am also planning a future purchase(say, 5-8 days) of 4 Profile Panels to save money over purchasing 4 more Mega Panels.
Now, this is the strange thing:
The Mega Bar 50's and the Mega Panels do produce, for lack of a better term, a ROUND light, almost as if it's an LED can, just flat. Go figure!
Now, I do something with my Mega Panels that sort of limit what I can do with them, but hey, for what I do, it's perfect. I have them mounted on a 5-foot section of iBeam trussing and typically mount them on the floor, like this:
The Mega Panels are mounted to the trussing using ADJ O-Clamps and wired using Accucable 3-wire DMX cable. Power is from a hidden power strip in the mix. Set-up and tear down is super fast and easy.
My clients LOVE this configuration(center 2 up front, rear 2 on back bar, then arc'ed into a cresent for presentation). One client loved this so much he requested I NOT bring in additional lights as he felt THIS was enough light show on it's own. Thank goodness, because I was having to run 2 events at the same time and was pretty much shot to hell on lights as a result for the rave room. That bank served a 250+ sugar-high bunch of anime fans!
The Mega Bar 50s I like because they are cheap, compact and for the money, put out like a hooker trying to get a medical degree(OK, maybe not that much!). For the application I bought them for, the original 4 weren't enough, so I had to double up and get another 4, which was ideal. But, this is a large stage(36X20), and they were bought to supplement lights having to do a far throw appliation and they are more short/medium throw(ADJ 64 LED Pros). I did use my 8 Mega Bar 50's for my last second Halloween thing, and it was too much, but that's OK. We're talking lighting up my porch area.
Now, comparing the Mega Bar to the Mega Pixel, it's not a straight "apples to apples" comparison. It's more of a "Fuji Apples to a Red Delicious" sort of thing. While similar, they have a lot of differences, which may or may not be advantageous. The Mega Pixel units have little banks of same color LED's, which can be utilized for effect that a Mega Bar can't handle. The Mega Panel and Profile Panel have higher DMX Channel counts so I think it breaks up the pannel into I think 8 possible zones, which can be leveraged for effect, but the software I have can't really "realize" that in it's 3D Visualizer, and anyways, 7 channel mode is what I want anyways. The Mega Bars are straight up single color at a time wash lights, which isn't necessarily a bad thing. I do like throwing the Mega Panels into sound active mode.
Addressing how you want to light your band, I think a panel would be better, mainly for the bracket arrangement, but I also think some of your idea needs some work. I would suggest 2 Mega Panels per stand, either on the pole or hanging off T-bars(T-bar might be better). THis gives you better wash and coverage.
If you go with a bar, it really eats up too much "pole" real-estate if you want more than 1, and won't let you really do 2 at once. If you mount them on a T-bar, you have more options, providing what type of Mega Bar you go with. The Mega Bar 50 is a short one, so it gives more options.
Now, I'm getting 4 Profile panels to help augment the Mega Bar 50's. They will go in 4 nests of 2 Mega bar 50's and 1 Profile Panel per bank.(stage is divided into 4 zones). PRICE is a factor, because if it wasn't, I'd get 4 more Mega Panels. But future plans include Elation tri LED cans(16 total, 8 RGB Zooms, 8 Opti Tri Pars, or maybe just 16 of one type), so it's best to go a bit cheaper now to help support the Mega Bar 50s a bit more and then save the cash for bigger lights for the near future.
So, my recommendation is really 4 Mega Panels, 2 per side. If money is a factor, then 4 Profile Panels because they cost half, but aren't as bright either. If you want MORE lights for more money, then go with 8 Profile Panels, which would cost about the same as 4 Mega Panels. If going with pole mounting, get 4 ADJ O-clamps. If going with T-bars, use the bolts included or O-clamps, and leave the lights on the bar. Pre-wiring saves time.
As far as controllers, I'm really partial to the MyDMX software. I'm not interested at all in the UC-3 controller. That's not to say it's not good. It's just that due to what I do, the UC-3 isn't anything I'm interested in. I do know that if you take the time to program an ADJ DMX Operator, it can be very easy to use and very convenient when recalling scenes.