advice on systems

[mike31154]

If you're planning to go with a sump, you won't need much additional filtration other than a skimmer. Depending on sump size (big as you can go), you'll be able to fit most of your gear in there to run the display, include a refugium if you wish... etc. etc.

My current 75 gal is sumpless but I have a 90 which will include a sump/refugium in the basement. I'll be using a used 65 gallon tank as the sump and may end up using the 75 once it's empty for additional volume/options. Lots of room in the basement, but it will require a fair sized, pressure rated return pump to move the water back up to the main floor. If you put the sump under the display, your return pump won't need to be as powerful, but your sump size will be limited by the cabinet and access may be a little tighter for mainenance.

Congrats on the success with the small, sumpless tank you're running now! One more thing, most 90-120 gal tanks are 48" long so you may need to go with 48", 54WT5 lighting, depending on livestock you intend to keep.