I have a 4.8, really wanted 5.5 but didn't want to wait for a new one (was a 4 month waiting list) and got a bargain on the 4.8 that was less than 12months old, mine is a tiller steer and i will have a side console put in it soon. There is a few 5.5m and 6M ones around Brisbane, get on Instagram and search hashtag galeforce and have a chat to them, or a few charter operators in Harvey Bay run them as well, so maybe book a charter. 70hp tiller steer is hard work after 30mins of driving.
One great thing about having one built is you can really get them customised, like the height of casting deck, would love mine lower as it gunnel height, the self draining deck and deck wash is good, but i keep bungs in the scuppers most of the time as it does get a bit of water on the floor. I have met the owner and have spent a few hours at the factory and they were really good. If i was having a new one built i would go with a larger engine, the 4.8 will take a 90hp, i would also have trim tabs put on, they make 2 size consoles, while the larger one looks better and would keep you dryer, it does take up more room. They also do a offshore transom which i think i would get.
It will all come down to how much you want to spend, when i looked at new and told them what i wanted i added $20k to the base price.
If you want to go for a run in the bay one day i don't mind taking you but the 5.5 will perform differently.