We went from dell Quay 15ft to a 5.4m searider. Less room even if longer rib, but you will not regret it
I would suggest a searider or humber or ribcraft or tornado of similar size. Typically 5.4, 5.8 or 6 in the above brands.
There are others, some good, some bad, but the above are fairly well tested and will last if looked after. Budget obviously prevails. Good luck and enjoy. Anything you think of looking at, just post on here, there is plenty of people here that will pass comment on suitability for you if you state what and where you will be using it.