I have a 10gallon tank with 1 male betta, 6 neon tetras, and 3 albino cories.
I originally wanted 6 pygmy cories, but there are none available in my area.
Pygmy cories are great for cleaning up left over food in the tank. They do best in groups no smaller than 6, anything smaller than tends to stress them out.
Since I did not have any pygmy cories available, I went with albino cories. These are about twice the size of the pygmy cories, so I went with half the amount so I wouldn't over stock the tank. Albinos usually do best in groups no smaller than 4, but mine seem to be very happy and they are very active. My betta gave them each a peck when they first met, but after that, he seems to have be-friended them. He often goes to check out what they're eating and sample what the cories have lol.
I'd say neon tetras are close to the harlequin rasboras and they were a close second when it came to me choosing which I wanted. However rasboras grow almost twice the size of neon tetras (neons-3cm, rasboras-5cm), but still need to be in a school of 5 or more. I had originally bought 5 neon tetras, but my betta mauled 2 of them the first day and one died a week later (body was unharmed so I don't know what happened to the third). So I went back to the store and bought 4 more to complete the school. With 6 in my tank, I find they tend to swim around a lot more and after the first day, my betta has totally ignored them.
I'm not sure about the cloud minnows, all I know is that they do like cooler water, their maximum temperature being around 79*.
That all being said, if you are going to go with the rasboras, I would stick with just a school of those and nothing else. If you are going with the pygmy cories, you could probably do a school of about 8 or so, however from what I've read, you might want to reconsider the substrate if you want corydoras, it's my understanding that the Floramax substrate has too many sharp edges. Again, I'm not too sure about the cloud minnows.
A site that I used to see if I was over stocking my tank was http://www.aqadvisor.com/
It's not always 100% right, and it doesn't take live plants into account, but it's a great guideline :)