We didn't establish if our questioner was buying a left or right hand car, or if indeed they are a UK driver?
Seems like people have jumped in here with, ahem, both feet.
Suggest you test drive a few automatics in different makes and get a feel for what you are comfortable (and safest) with.
I'm left handed, but do a variety of things right handed, oddly enough. I drive a clutchless car in the UK with manual and automatic transmission in one gearbox and have no problem using my right foot for braking and accelerating.
So, my own view would be that as long as you are comfortable with the switch and have some familiarity with automatic driving, go for it - as long as you are confident that you can drive safely!
And how nice it is that you are still driving at 76. Suggest, with respect, that you ebay your bus pass!
Best wishes.