Only advice I can give is from my own experience... I am still newbish while pushing close to 2 yrs already....

But my fuge is not apart of my sump and I recommend this route to anyone starting a new tank.... The fuge, while some consider ugly has really cool stuff going on and at some point I want a bigger fuge... So if you do set up a remote fuge go as big as you can...

I am running mine without a sand bed and I can't stand the crud that builds up on the bottom. Idk if a sand bed would benefit me anymore but I haven't had no crazy algae out breaks EVER!..... I do have some live rock in there for the pods to hide out and breed, I would recommend rubble or a few good sized pieces... I have chaeto and caulpera, I recently added some dragons breath and a mangrove..... Going to see how those do....