I just made my own roach bin. They are very easy. I have ordered roaches from several different places and have had good experiences with all of them. Check out DubiDeli.com, Dubiaroaches.com, or of course the site sponsor ABDragons.com. I have ordered from all of these and been happy with the roaches I received.
ABDragons also has the flexwatt heat tape. I use it with my dubia and it works awesome!
The number of adults you get depends on how many animals you are feeding. I would recommend about 20 females and 5 males per animal. Some may say this is more than you need, but I would rather have extra than too few. I am feeding 3 panther chameleons and I started with about 200 females and 60 males. Now I have several thousand mixed sizes and feed off 150-200 dubia every day. Unless you also order a bunch of smaller (feeder sized) dubia, do not feed from the colony for 3-4 months at least to let is get established. Alternately you can order a couple thousand small dubia as well and feed from them immediately, this is simply much more expensive.
I also plan on starting a 2nd colony soon because I have eggs incubating and want to be sure to have enough for the young ones when they hatch.
I think you will find that dubia are SOOOOOOOO MUCH BETTER than crickets in just about every way! Good luck!
Also I am more than happy to answer any questions you may have about keeping dubia.