I am not sure what your neighbor meant by "rerigging" a large steel sailboat. But if you remove the masts, you have to make some significant modifications of the ballast. If not you will have an extremely unconfortable boat--and perhaps even to the point of danger with a rapid roll. Sailing is relitatively easy--and with roller furling, electric winches etc it is physically relitatively easy--but this list is about power passagemakers.
As I have traveled--and lived in different parts of the world, my ideas have changed some. On the West Coast a deep draft boat is fine--it is rare that you will have a problem with 8 feet. I had a boat with 6 1/2 feet of draft and it became a problem on the East Coast--and somewhat restricitive in the Bahamas. 5 1/2 feet is better--and so is 4 feet, but that will be rare.
For passagemaking the range is obvious--and I think that between 2500 with a reserve and 3000 miles is enough. If you are going from the Canal to Galapagos to the Marquesas, to the Societies you will need 800+ to the Galapagos, but 3000 miles range to the Marquesas from there.
There are certainly advantages to steel (I saw a boat which was severely damaged in a hurricane, where the holes were just welded up and the boat continued on a circumnavigation with a badly deformed starboard side) But there are disadvantages--and there are as many or more steel boats lying on reefs as any other kind. Fiberglass is certainly still an excellent material.
The stability is a major issue--both initial and reserve--and the danger of rolling over or pitch poling. The consensis is that fitting active fins or paravanes will make many boats which are well designed comfortable for passages.
The ultimate stability is both a design and a decision process--when to deploy a series drogue or sea anchor vs run off. How well will the boat power off a lee shore?
Survival of waves breaking on the boat--or better yet, the boat falling off a wave, landing on its side and not breaking windows and cabin structures is probmatical.
This is where many of the coastal vessels fall short. One can make lexan or heavy plexiglass storm shutters (or precut plywood) Attachment is easily handled with recessed nuts and bolts.
One thing which bothers me on may of the "passage makers" is that there is not adequate room on deck for sheltered lounging. I like to be out of doors--and it seems as though many boats are not designed for this.
In the Force 50, we never had air conditioning, but instead had excellent ventillation--dorades, wind scoops and hatches, plus awnings which would cover almost the entire boat. Lots of places to comfortably sit on deck both under way and in a harbor.
Are water makers, airconditioners, generators, dishwashers, washing machines,inverters, fancy chart plotters etc necessary? No they are conviences. We made a passage to Hawaii only utalizing half of a gallon a day of water per person aboard--and did fine. Are the luxaries necessary? No--but they do make it more comfortable.
Now, looking at Bob England's K K 54--it has 1500 gallons of fuel. Some sites say this is a range of 3000 miles--that seems a bit optimestic at 8 knots ,considering head winds, seas and currents--but if you kept the fuel burn to 2 gallons an hour (probably about 6 knots) you would have 4500 mile range (no reserve). Most of the photos of the KK 54's in ads have some loose furniture--that would have to be resolved and fixed setees or bolted chairs in place. The windows can have shutters--and doors replaced or reinforced. Is the deck house structure sufficient to take a roll over? This may be questionable--but how often do roll overs occur? Same for pitch poles--and this is where the weather factor and judgement come in.
So would I take a modified KK 54 to the S. Pacific? Yes. Would I take it to the Southern Ocean? Probably not--but remember that a stock Defever 40 LRC is circumnavigating S. America and doubled Cape Horn (Ok good weather) Maurice Nunas' Akama is a KK 48 whale back. I don't see where this is any more seawothy than Bob's 54--in fact the 54 is probably more seawothy.
So Bob--why not modify the KK 54 and go?
Bob Austin