A couple of questions.
Do you sail a lot in light air? Racers need great light air performance but not all cruisers. If you are like many and start the
engine when boat speed drops under 4 knots then you might be better with sails that are well suited for 10+ knots. Remember, that most modern designs like to be sailed with relatively little heal. Many people carry far too much sail for best performance. You
current situation is like having a reef tied in. Something more people should do.
How does she steer now? As others have suggested, balance can be more important than square feet.
Weather helm that requires 20 degrees of
rudder is like dragging a huge bucket astern.
Do you need new sails anyways? Upwind, new small sails with great shape will beat blown out bigger sails. Also - after considering balance - you could:
1. Build a lot of roach into the main. Besides helping downwind, the roach provides a lot more upwind
power from the upper part of the sail. John Dashew used so much roach in his cruising boat series that the leach overlapped the backstay by feet (he found there was surprisingly little chafe). He writes about it in his
Offshore Cruising Encyclopedia.
2. Have a new
genoa made with the foot closer to the
deck. This hurts visibility but greatly improves power upwind by creating an "end plate" between the bottom of the sail and the
deck. Much better than a few more feet of hoist.
3. As you suggest, get a nice big off the
wind sail. You might consider something flatter than a typical
spinnaker that can be carried somewhat closer to the
wind (look at the Doyle MPS sail)
All of this costs
money, but I assume you are saving some
money in the
purchase price due to the modified rig.
Carl