16 Gallon nano reef help!!!

Okay, so I currently have an 8 gallon Biocube that has been set up for about 6 months with LR/LS, a few pieces of coral and a yellow tail damsel. My LFS just marked down a 16 gallon bow front for a ridiculously cheap price and I figured it would be nice to have a little more room to work with! My main question is, after the tank cycles and such, I'll move things over and I want to know what can live with my damsel? I also have a domino damsel(I didn't know he got so big, didnt do the proper research..but i'm giving him to a friend with a larger tank!!) They get along swimmingly(hehe) but when it's just my little blue one, what will he be okay with? I've always loved clowns, gobies, and blennys. What is compatible/what will be okay in a 16 gallon. Also as I was reading through many threads, people were saying you don't need a filter in a saltwater tank??? I have one currently because it came in the tank but do I not need one when I move over to the 16G? Thank you for any and all advice!!!!!!!!!!!!!! OH, and do I need a protein skimmer? I don't have one currently, should I get one for the 16G?





ALSO, right now I've just been buying SW from my LFS but would it be cheaper moving over to the 16G to start mixing my own?