Chris, assuming you're mounting your panel horizontally, the windage should not be very great. Of course, when the boat is heeled, the panel is longer horizontal, and it's in such situations that you care most about windage. How much do you expect to be heeled over? At 20 degrees, one square inch of panel diagonal is 0.34 square inches of windage (approximately proportional to the sine of the angle of heel). A 120W panel is 1600 sq-inches, so that's 540 sq-inches of windage, about a third of my mast's windage. Of course it's not as bad as spars and things, because it's at quite a slope, so it won't hurt you as much. I suspect very little.
Maybe MaineSail can do a wind tunnel test on windage due to solar panel at various angles of heel.
Anyway, are you adding a hard dodger of any kind? You can mount your panels on that and then you're not significantly altering the windage. You could probably build something around/beside your windvane to mount panels on, but stuff mounted on the transom tends to get damaged in rough weather I hear.
As for your energy needs, a laundry list of equipment does not an energy budget make. Maybe instead of asking how much panel you should by, figure out how much panel you can install, and then see how much power you can afford to consume on a daily basis.
Here's a quick description of what I did (because I was bored, not because I'm in your situation):
1) Make an energy budget. That's a spreadsheet with your items down the first column, their draw in amps down the second column, and the hours per day that you spend using each one down the third column. The fourth column has the product of the second and third columns.
If you have different energy expenditure "regimes", you can repeat the third and fourth columns many times; once for "passage making", once for "weeks at anchor", once for "at the dock", whatever. Your behaviors and equipment demands will obviously be different in those circumstances.
2) For each regime, sum up your daily amp-hour draw. I also added a 10% fudge factor at this point. Put this below the last item.
3) Next work out what you get from your panels/turbines/etc. For me it's just panels, so I put rated wattage W, then charging voltage V (not 12), then effective hours/day H of performance at rated output; the daily output of my panels is H * W / V.
4) Result from step 3 - result from step 2 = daily amp-hour surplus. This could be positive or negative. If it's positive, good for you.
5) If it's negative, your next task is to figure out how many days you can stay off grid in each of your regimes. Take your house bank capacity in Ah, and set a safety factor equal to the fraction you'd be willing to draw (say, 40% of total capacity). The product is your effective battery capacity. Divide that by the result from step 4 to get the number of days before you need to go find find a power outlet.
If your goal is to be off-grid and self-reliant, I think the result from step 5 is a good metric for how well you're doing at that.
If you'd like, I could send you the spreadsheet I created to do this. It's fairly humble compared to your plans, as I'm just daysailing/weekending, but you should be able to expand it to cover your needs.