ANY hub that you buy will almost certainly need weatherproofing before use.
How do you weatherproof a hub? Pack more grease in? Wouldn't that only apply to loose-bearing hubs? Also I thought most cartridge bearings had weather seals?
With few exceptions the seal type, bearing specification and grease fill chosen by manufacturers of 'sealed bearing hubs' is a long way from being optimised for the task in hand.
To make a typical cartridge bearing hub last longer
1) remove the bearings (which NB may damage them)
2) replace the bearings with ones of the correct tolerance/specification (in many cases)
3) remove the inner seals from the bearings
4) fill the hub with a proper lubricant (eg land rover front swivel SFG )
5) refit the bearings
6) check that the QR loading doesn't preload the hub bearings
7) enjoy.
To make a cup and cone bearing hub last longer
1) remove the LH cone and locknut
2) check the RH cone and locknut are properly tight against one another (use threadlock if you have it)
3) lube the bearings with lots of SFG
4) adjust the bearings so that there is a little free play that just disappears when the QR us used to tighten the wheel in the frame
5) enjoy
The latter requires one or two cone spanners and a pot of SFG. With practice (and a hub vice) you can set up most hubs in a few minutes this way.
BTW I don't quite understand why you are insistent on using a campag freehub body; this is only available in hub designs that are intrinsically weaker than is possible with shimano-compatible ones, and the latter can always be fitted with a respaced cassette so that it will work with campag sprocket spacing. There is vastly more choice in shimano-splined cassettes too.
cheers