Welcome to SB..

I think your question couldn't be anymore open ended if you tried. Here are a few questions you need to ask yourself (and the others). I am sure other forum members will add some more.

1. What is the budget (post important Q for establishing a starting point)
2. What is the ongoing maintenance budget.
3 Where do you intend to keep it
4. Are you fishing out wide, coastal, in an estuary ect
5. How many intend to go fishing at the same time.
6. Will be a penned boat or on a trailer.

Notwithstanding the answers to the above questions, my suggestion would be a Haines Signature 650 (21 foot) or similar. For starters they are made for fishing. But are trailerable, so storage will be free (rego on the trailer is bugger all. I think about $75 here in WA). If you do not want to drag it through the CBD you could always store it at a boat yard or club on on dry stacks (I assume they are around in Vic). They are just as much at home in an estuary as they are out wide and with the variable dead rise (and heavy hull) they are very safe and comfortable out to sea. You could fish all 4 of your group members but 3 would be comfortable.

Comparable boat would be the Haines Hunter, Boston Whaler (would be my choice if it didn't come down to money), a Conquest 28 (but starting to get to big to tow... Well for my liking anyway, but is starting to come with comfortable accomodation), and a million different aluminium models (but in my opinion only, not in the same league as the boats mentioned).

There is a forum member who sticks his head into here from time to time, JBshack who owns a boat yard here in WA (not much help for you I know), but he may be the best to elaborate further.

you could start with hiring a small fishing boat on a few weekends there lots on the east coast it would get you started
see how you like it plus you get some idea of boat handling .
Plus go do a course to get your boat license
Im not a Noob by the way just a grumpy old man