Do a extensive research and reviews on each of your fish. I think too many people on this forum and other forums cram their SW
tanks with too many fish. The best home for your stocking is a judgement call by you and your knowledge on each of the different kind of species.
From what I learned from people who have kept fish alive for 10+ years, dog-face puffer does best with 100g of water for themselves. Easier to maintain the water and puffer lives in a less stressful water.
The easy part of owning SW
tanks is buying all the equipment and fish. The fun and challenging part is maintaining the tank and keeping fish alive for as long as possible.