It's never good to artificially alter the pH, so if you can, go with fish that like more alkaline pH. I don't know if Neon Tetras could adjust to a pH of 8.0, as Neons are very delicate fish, but maybe some other species will. Many tropical fish do adapt to higher pH. The point is to have a STABLE pH at all times, and not a constantly fluctuating one.
Besides, you do know that you have to get the smallest possible fish you can for the 5 gallon tank, right? Supposing the fish won't be larger than 1" (when they're adult), you can get 5 of them AT MOST for this tank. I personally wouldn't even keep 1" fish in a 5 gallon tank. But that's me. Hmm, how about a
betta? Do you like Bettas? Maybe you could save one Betta from that horrible cup of water it has to live in at a fish store. Five gallons is much better than 1 tiny cup.
I don't know about any white substance settling on gravel and decor as a result of the cycle, but I do know about cloudy water. Cloudy water is a sign of a bacterial bloom - which is good.