You can’t book different class tickets on the same PNR/booking. Your sons are adults so book them on one record and you on another record. No need to call the airline (presumably AA), just check online award availability and book. AA.com offers a complimentary 5 day hold for award tickets. Once you’ve ticketed, you can ask AA to link the tickets, which may or may not work. Even if the link doesn’t work, there is little downside as the operating airline has an obligation to get you to your destination in the unlikely event of IRROPS. Hopefully, you are booking QR or EY and not scam charge crazy BA.