Hi new to this site and have a question..

[molotov]

First of all, welcome to Canreef.

You could definetely do a chest or trunk to house your sump. The only thing I can think of would be to make sure it's well vented. You'll also need enough height to allow for a skimmer. Also keep in mind there will be a lot of pipes for your plumbing that will be coming into and going out of your chest/trunk.

I think if you could hide all that somehow it would be quite a neat designer type idea. I like it.

good luck