quick update in case is useful to anyone, I phoned up (having found availability for x 2 in suites) and they made me do mine on my PC (whilst on the phone), then had to give them my booking ref and they did my son's at their end as couldn't be done online, and gave him 15% online discount on his booking and linked it to mine, so we are now 2 x suites from Singapore to LHR in July. Husband is in first on 777, three hours later and waitlisted for suites on our flights. Fingers crossed!

thanks for all the help :-)