Wood, wood, wood.
JJ work out a budget and then shop it. As for the setups, that is something you are going to have to try. You can freeshaft or lineshaft. Tips are another preference, then there is the flopper choice, one big flopper or 2 smaller ones. The more you get into it, the more you will "fine tune" what works for you. If you want an Biller and can't get a local deal and need help, pm me.
As for size, I don't normally sell any wood guns under 50" to guys if I know they are shoot any kind of distance or fish of any size to them. Now, if you plan on shooting in really low vis or fish the size of mango, sheepshead, pinkies and alike a gun under 50" is plenty.
I plan on buying a longer gun in the near future, and the only exception to me purchasing another wooden gun (probably going to be a Riffe Competition Series) would be if I saved up for a Darryl Wong Hybrid.
As a owner of all models of Daryl's guns, I probably
wouldn't recommend the hybrid if you are scuba diving or free-shafting. You would probably be better off with an enclosed track. With the hybrid, the line crosses over the shaft and holds it into place since it is an open muzzle. Just about every other dive at some point I skip doing the line rap my gun cause another hogfish or grouper is in shooting range.
The 50" Florida Freeshafter that Daryl makes is worth its weight in gold on fish under 30lbs and is not much more than the Riffe guns.....You can pick them up pretty reasonably used. I have had guys use it on my boat and try buying it on the spot..... I love that little gun. I have shot cobia and AJ's up to 50lbs with it....
The Wong 57" MG Special is an excellent shooter. I take fish tipping 100lbs with it.....

As a matter of fact, I have a Wong 60" Mag Hybrid that hasn't been wet for 2 years because of the way the 57" MG shoots.
Sorry for the elaboration, I love talking about guns....