Mim is right, it's impossible for one board to cover "light wind" and 4.0/4.5 weather, period (don't get discouraged though).
What manufacturers usually claim (in this case f122, sails 5.5-9.0) isn't realistic, I guess for someone your weight it would be around 6.0-8.0. You don't say what is exactly your typical lightwind day, and what is the biggest sail you plan to use? I guess you could go for F133, it will carry around 9 for you and keep schlogging comfortable. You can keep your 95 for high wind (what's that board btw?) or replace it with some ~100l.
True 4.0/4.5 wind for a 90 kg sailor - that's 95 l board territory, or if it's holey, around 105l max.
One more thing: if you really need a board that can handle ugly conditions, but with a bit more volume, maybe you should look at the bigger Kombats/Kodes (rather than F).
That's probably not what you wanted to hear, but trust me that single board doesn't exist yet (and I've tried).