I think this should be possible, as long as your wife is happy in the navigator position and you are OK with being the bug-shield. Having the larger person on the back is difficult, but may be possible with unusual designs.
I'm always banging on about how important bike fit is and a tandem is no different. Do make sure you try as many as possible before buying as it's a big investment. If you are in or are visiting the UK, you can try the Tandem Experience, which we found very helpful. We visited a (fairly) local bike shop and they found us a bike which fitted us and gave us some tips on a harmonious ride. It would be worth calling to discuss sizing in advance.
SJS Cycles/Thorn make popular touring tandems and they do a L/Xxs size frame which might fit you both (I couldn't see precise numbers).
Note that it's very likely you'll need different crank lengths, or you may argue over gear selection.
There are any number of frame builders who could build something to fit you both, but that's a big investment, especially if you haven't had a chance to ride a tandem together properly. It's not just the bike fit that counts, you need to have at least a day out to get used to it and ensure you can both enjoy it and the compromises involved.
However, don't let that put you off. One of the best things about tandeming is the easy conversation on a long ride. The next best thing is long, gentle down hills. Have fun.