Hi Terry and welcome-some great advice given so i won't add-except to say i agree in that see what they've been eating already and steer clear for now at least of supermarket brands as Alan said-i've found they tend to give the trotts and make dumps even smellier and it can often work just as much paying for fresh food as brand food-and with fresh you know exactly what they're getting
Good luck with your new additions and plzz post some pics as soon as you can-look forward to seeing them and hearing all about them