Purchasing new fish tank help

[Kevotron]

Heres a short background story
I wanna get out of my current 120G that I bought from Aquagiant years ago
I didnt know much back then and had little funds... hence I settled for it
The plumbing of the tank is just horrendous, Overflow Box and sump poorly designed

Should I Buy Used from a fellow reefer or brand new
If Brand new any recommendations ?
Only 2 places I know is AI & Marine Aquaria