Aquatek will have their big sale next weekend (aug 28th) check their sponsor link in the forum for details. "Tunze equipment 10% OFF"
We are using the Tunze nano 9002 (rated for 75g) for our 45gal. It is internal mount and takes very little space but comes with the internal pump. It runs super quiet and very efficiently.
It was listed for around $160 retail which is much the same to some online suppliers. If you decide to go, get there early. But not sure about any other local sources.
You can always post on the "want to Buy" section. See if you get any feed back.
Cerith snails work great on the brown diatoms. Nassarius do stir the sand bed more like "bulldozers" but they are carnivores so they will need to be fed.
Some blennies, like tails spot or lawnmower will eat the algae, but be sure you know which ones are reef safe and what your size limitations are for your tank size. Lawnmowers need lots to keep them sustained.
We have a tailspot, he is eating both hair algae and flake food as well. Between the skimmer and the Blennie we are starting to find a good balance with algae & tank inhabitants.
Good luck.