Hey Ryder,
I have some tubing and adaptors that I get cheap, its used to extend landys breather pipes and bring them up to the snorkel level. When were out and about next I'll have a look underneath see if thay are also compatible with your breathers.
As for water proofing its a tough one,
I would look at it in 2 stages,
1, Keep ignition electrics from the ecu's to the dizzy cap water tight,-Seems easy but the trick is to also keep them accesable in case water does get in because it probably will!
2, Air intake high level reduce hydraulic lock and possible engine damage,
Personally if i had a petrol I would drill and tap a couple of small holes into the distributer and run a vacume pipe in and out of it to keep it clear of any condensation residue (keep the air moving). This is a bit extreme however I have seen it work well once on a rangie, however it did have new ignition system prior to install aswell. The rest I would just make sure they are all in good nic and spray regularly with the magic WD40!
Make sure any snorkel is fully sealed and tested prior to dunking! not worth risking an engine for a bit of extra silicone. Jai