I would recommend you have a look at LeFrenchMobile.
We offer SIMcards that do not expire, everything is in English if you do not understand French and we now offer even lower tariffs. Our tariffs are 35% lower than the regulated EU rates, and since it will be you and your wife; and if both of you choose to be LFM users; you can talk to each other for only 7cents per min.
I honestly think that this solution would suit you best, as one of your main criteria is that your SIM and credit does not expire.
Hope to see you become part of the LFM family.
