hey there congrats on your twins
best advice is to join your local AMBA group as they are a wealth of knowledge from 'those in the know'. Most girls with a toddler and newborn twins go for either the valco with a toddler seat or the Fitnesswise with a toddler seat. There is a new triplet pram out recently which is a twin pram and the third baby is on the hood of the pram. If you look up the AMBA website, it is advertised there and there is pics!
IF you want more info about anything- please PM me!
good luck and let the fun begin!
odette