Ooh definitely a Weenotions and then maybe something from another WAHM too? I bought an XS fitted from Orange Diaper Co and that was his first cloth nappy, he's nearly grown out of it now but I don't think I'll ever have the heart to sell it
Maybe an XS Dunk n Fluff or something from Holdens Landing? You'd be waiting a while for a custom but a lot of UK online stores have them in stock, Kingdom Fluff have some nice DnFs at the moment!
One thing I will say - if you think you're having a big baby, dont buy everything small. My little fella is 9 weeks old and he's already out of most of his smalls, I ordered him 2 Weenotions pockets recently and I'm SO glad I got mediums rather than smalls! He was 9lb at birth so quite big and he's been a little chub monster ever since x
I would have said WeeNotions but due to the RNW discount they will not rush any orders through to get them done by a certan date and the expected wait time is 2-4 weeks so you may not get it before bump arrives. Other than that definitely Puddlekins, Hollow Oak or Jimmy Riddles. Some UK stockists have US WAHM fluff in stock such as Dunk n Fluffs and Holdens Landing but generally they start at small rather than newborn.