Welcome to the forum fish4all! Lucky for you, I am fond of lengthy posts = )

The diet for the roaches that you listed sounds excellent, both for the benefit of the frogs and for the benefit of the roaches. I like to think of it this way: The reproductive success for roaches isn't so dependent on variety and quality of food... they will thrive so long as temperature, moisture, and space demands are met even on a poor quality gutload. The variety and quality of the food you offer to the insects is going to more directly benefit the frog. You could probably raise an excellent colony of roaches purely on some dog food and lettuce - but by offering a nice variety and nutritious foods (say Collard Greens instead of Lettuce) you will be able to pack more goodies into the feeder for the frog.

I would HIGHLY recommend getting a started culture or feeding a few roaches right off the bat to your frogs to ensure they will accept them readily. Blaptica dubia can be a hit or miss with some species... particuarly because they seem to have an uncanny ability to sense danger and will often bunker down and sit still for some lengths of time. They are excellent feeders and highly relished by those that will take them, but I've found that some nocturnal, arboreal species rely heavily on movement to encourage a feeding response.

Perhaps because you have a smaller species, you may consider a couple of different species in addition to dubia. Blatta (Shelfordella) lateralis... the Red Runners/Turkistan roaches are a favorite amonst my Rhacodactylus geckos where I have a few animals that will turn their noses up to B. dubia. Turkistan roaches stay smaller and max out about the size of an adult cricket. They also do not fly or climb, but are a little smellier than B. dubia (don't let this discourage you, I assure you they are nothing like crickets). The main kicker is that they lay egg cases. This makes them more prolific...capable of cranking out 1-2 ooths monthly. The downside is these ooths can require a bit of tender loving care in their humidity needs. If this is an option you'd like to consider, I would be more than happy to go into specifics.

Lobster roaches are another smaller and prolific option, also attaining a size similar to that of an adult cricket. The major downside to these guys is they can climb glass and smoother surfaces (and they too are smellier for a roach). Lobsters are probably one of the most prolific feeder roaches on the market and give live birth, making them virtualy effortless to culture if you can get past the climbing.

Given the size of your frogs - I think these three species will be most reasonable and most readily attainable for you. So in a nutshell: Dubia are great, but make sure your herps will take them. Be somewhat persistent; my friend's milk frog took a few tries before he actually ate one and from that point forward he began eating them like candy. If you want smaller and more prolific roaches that move around a bit more and attract pickier feeders, go with lats or lobsters = ) It seems these two species are softer-bodied as well, which may influence feeding preferences in some species. Nutritionally speaking though, all roaches are virtually the same in composition.