[makana]

It sounds like you have a pretty good handle on what you want. I have a nanocube so its not exactly the same.

Flow behind the rock is the challenge. So far I have not found anything that works. I would like to get an elbow and point the flow down but I can't find fittings that are the correct size. Mine has two return pumps and I've found the overflow can't really handle them both being on. Something to keep in mind when considering a larger return pump.

Most skimmers don't allow you to open the lid. I went with a HOB skimmer because it didn't get in the way, but I had two pumps get hot and melt. I don't run a skimmer anymore.

I have had no issues with the JBJ chiller that mine came with. I've been using it now for about 8 years. It has saved me a couple times when heaters have failed and stuck on.

I currently use a jebao powerhead for flow. It is small and has strong flow. Also, not crazy expensive.

Good Luck!