Actually the South Beach way allows for bread, rice and pasta, just not the white, overly processed kinds. It encourages small servings of 100% whole grain versions of all of those items (and brown rice in place of white and sweet potatoes in place of white potatoes) in phase 2 and beyond. So a "pasta night" on SB, would be a small side dish size of 100% whole wheat pasta (1/2 cup is a serving of grains) with a lot of vegetables, no sugar added spagetti sauce of some kind and some kind of lean protein or fish. We like to saute up a lot of zucchini, Classico makes a number of styles of sauce that work and then use either shrimp or scallops, mostly because our older daughter doesn't eat meat, but will eat fish and shellfish, so that is what works for us instead of a meat sauce. (but a meat sauce with lean hamburger would work too!)
So that is really just one example. There are lots of good carbs on SB, even in P1. SB is more about learning to discriminate between the heart healthy and non-heart healthy versions of each of the main three macro-nutrients (fats, proteins and carbohydrates) and including all of them in a fairly balanced dietary program with a large emphasis on lots of vegetables every day.
????: South Beach Diet Forums http://www.southbeachdietbulletinboard.com/introduction-forum-just-say-hello/5603-hello.html
As far as a more specific suggestion, I'd find the sticky topics here in the P1 forum here for the food lists and the meal model for how to combine them and be aware of any limits on any specific foods and give it a go! It's more of a full lifestyle change type program, so don't sweat the occasional mis-step. Just learn as you go and keep on going!
Good luck and best wishes to both of you and good for you for continuing to be active in your 70s!

That's pretty awesome right there!