It seems to me the question is: do just you want to sail, or to sail well?
You can get across oceans and round the world
with just a furling jib
and a main. We have very experienced friends who do that.
However, you can sail much better than that if you want/enjoy actually sailing the boat (which many cruisers and most delivery
captains don't). You can go downwind with just the furling jib, but you will go much much better (faster with better boat balance and easier steering) with twin jibs poled out. You can heavy air close reach with either just a deeply reefed main or a deeply reefed genoa
, but will go much better (again faster and better balanced and more versatile) with a staysail and deep reef. Etc etc.
Perhaps it's a "vanity project" to enjoy sailing . . . I suppose that's exactly true. And if that happens to be one's vanity then ways to fly other sails are in fact very rewarding.
Now there are all sorts of ways to do it. The old reliable (back in the hiscock days) was twin side by side stays. We had that on our first boat. Some people then made them fore and aft stays, with various spacing between them (close = solent, far= staysail). Most recently people have been using high modulus rope
luff sails with continuous line furling and 2:1 halyards (this is mostly what we do on our current
boat, except we also have a dyneema
There are also some potential safety
benefits of extra stay and sail options . . . .but honestly they really rarely come into play (note: Beth disagrees with me on this, and believes this is a significant factor).