I just picked up a 4/02 for light duty tuna chunking and deep deep drop cod and tuna and the occasional florida gag trip.
How much 80lb hollow does this thing hold? How much of a 80lb mono wind-on would you go with?
I don't know how much it holds, but I would use either 60# or 100#. The 60# line is quite strong and has been testing well over 80 lbs. actual breaking strength this year, the samples I've seen have been betweeen 90 and 105 lbs. ABS.
If you want more bulk (abrasion resistance) in the line, I'd jump to 100#. It's a 12-thread weave and you can get more of it on the reel than the 80# which is a 16-thread weave and probably just as strong as the 100#. The 80# is a nice braid for threading mono into.
Regarding the wind-on length, that depends on fish, structure, drag level you plan to run, type boat, etc. 10' handles most fish in most environments and let's you put more braid on the reel. (Leader Length)
The reel holds lots of line. I'll go with 80 lbs braided line as it is good for tuna and deep drop. The length of wind-on leader is your choice. Some prefer 25' or longer as they want to minimize for conneted knots to go through guides while fighting.