When I started here in 2010, I had much the same idea: I was looking for strategies to allow me to take a six-week trip to Scotland in 2014.
With that trip now two months away, I've found that the information gleaned here at FT has allowed me to take many more trips I wasn't considering in 2010--several to Italy, several to London, one to Dublin.
So, my first piece of advice is to refine your goals and just dig deeper here at FT. Given my circumstances, I am happy to supplement my decent cash travel budget with earned miles and points, but that's a personal thing. As a result, BA has been a go-to program for me despite the costs and fees associated with that program because I'm happy to pay coach level cash for premium level travel. I totally get why others find BA's program mostly worthless. When I began, I ignored IHG and Hilton, but over the last year or so, have found these programs much more valuable because of the geographical spread of properties--my two main programs, Choice and SPG, have a total of two properties in Scotland, one of which, the Turnberry Resort, was just bought by Donald Trump, probably leading to an exit from SPG.
This kind of analysis will give you an idea of the programs you should earn with.
Earning is easy enough at times, especially if you and your wife are willing to play the credit card game. Paying attention to the ebbs and flows of earning can also be helpful. After spending some time here, I realized that Amex tends to lower the spend requirment on the SPG card towards August every year. Chase has occasionally raised the bonus for the BA card from 50K to 100K as well as increasing the bonuses for its business cards. You can't always time your apps to hit the highest bonuses, but it's a strategy that's helped me build some nice mile/point totals without spending much more money.
Learning to spend wisely, using perfectly legitimate techniques, is the second half of that equation. Although just recently no longer allowed, the free stopover at the international gateway AA long included in its international awards was just one of these techniques. You've learned about the SW companion pass. There are probably tons more ideas you'll find useful after some research.
And, although you have a very good credit card spend, similar to mine, I have found supplementing with manufactured spending can help you hit targets you might not otherwise consider. For instance, I qualified for a BA/Chase 2-4-1 certificate last year while applying for and meeting the spend requirements for a number of credit cards. I could have easily met the spending requirements for the Citi AA Exec card, but boy, did manufactured spending make that task even easier.
Finally, for choosing specific destinations, I find the travel subforums at FT a valuable resource. Lots of specific information about sights to see and places to stay plus practical advice about the best ways to navigate through a country--whether by train, plane, car, or boat.
All of this has worked for me over the last four years. Enjoy your retirement and the increased opportunity to travel!