I don't know where you're located but I strongly suggest that you locate and visit a big recumbent shop. Be prepared to spend a couple of days there and ride, ride, ride.
There are so many recumbents in so many different configurations that the only real way to decide is to ride and compare them. I don't care how far away the nearest big shop is, you need to test SWB and LWB bikes. You need a shop that has several different brands of bikes. You need a shop that has various SWB configurations on hand to try out along with various LWB configurations. You need to try trikes, both tadpole and delta.
You might best plan a mini-vacation around this bike shop visit. Once you know what you like, then you can confidently shop for a new or used bike for yourself. Oh yes, don't be too suprised if the recumbent bug bite your wife also!!
Good hunting!!
