We are leaving in two days with our 13 month old twin boys. We will be flying to Orlando. Me, DH and DGrams. WEe only bought three seats (I know we might regret this). They have open seats on the way there, when I called the sirline last night and asked about bringing on the carseat if we got a seat and she said no they are only for purchased seats. Which I understand. We are bringing the carseats, everyone said the ones you rent are gross, should we check them or can we gate check them? Will they let the boys just sit in a seat or do they have to be in a carseat? We are flying Sun Countr. Thanks for any help.