Thanks for your comments.
What about the possibilty of having the inner stay set up with a smaller jib which would be used when winds go up e.g. above 20knots ( ?) and the furled genoa starts losing shape and becomes a bit difficult to set up properly, especially upwind? The genoa would then be furled in completely and the jib is furled out. Does anybody have any experience with this setup?
What you are describing is what is sometimes called the "Slutter" rig - cross between a sloop and a cutter. It was popular with some boats in the 1990s but the main drawback is that use of the genoa is compromised by the difficulty in tacking with the sail set because of the limited gap between the stays. So the staysail effectively becomes the working sail and the genoa only used in light airs off the wind.
If you are going to buy a new sail then probably better to get a smaller genoa, say 120% that is usable over a wider range of wind speeds, certainly greater than 20 knots and better when reefed for higher wind speeds because there is less reduction required. The slight downside is that you may lose a bit of speed in light airs, but with a well cut smaller genoa (which is much easier to handle) doubt you will notice the difference except off the wind where sail area does count. In lighter airs, though a cruising chute or similar on a furler is a lot more effective than a heavy genoa.
If you intend long downwind passages then having your existing genoa cut down to match the new smaller working genoa would enable you to use the inner stay to set twin headsails.
Large overlapping headsails have fallen out of favour recently with a move to smaller headsails and furling light weather sails to fill the gap off wind. As ever, though which strategy you choose depends very much on the type of sailing you do, the size of your crew and how much you want to maximise the performance of your boat.
There is no one right way, but the suggestions above are based on my experience of my last boat and current one. My last boat was a 37, essentially a smaller version of yours, originally used in the Med where the large genoa was good for the usual light airs. However when I got I back to the UK where there is more windward work it was tough tacking with such a large sail and in fact I discovered pretty quickly that it actually sailed better with the genoa reefed even in lighter airs. When I changed to a newer type 33 one of the key factors in the decision was the much smaller jib (105%) which makes short tacking easy and better pointing. The sail does not need reefing until well over 20 knots. Downside is off wind performance, but with a furling cruising chute which can cope with up to 15 knots.
