The site is definitely not very intuitive. For the nappy, click on "fitted diaper" in the box at the top left, then click on the size you want. You can either pick something in stock, or for a custom (all she has in XL at the moment) you specify what you want in the comments box when you place the order (xxx fabric for the outer, soaker to snap in front or back, OBV-topped soaker [not sure you actually need to specify that but it won't do any harm]).
For the wrap, same deal: click on Covers, then Wool and PUL Covers, then either choose an in stock or "embroidered or print outer PUL cover YPA" for a custom. YPA means you pick all, YPS means you pick size. Again, you specify everything in the comments box (fabric or PUL colour, and embroidery number for PUL; you can also pick the colour for the fleece inner and the serging thread and snaps, or leave it up to her). She has just about any colour of PUL you can think of, I probably still have the list somewhere or I might even have posted it a while back.
I'll measure my large for you and see what the biggest thigh setting is.