Re clothes, just buy the basics in newborn size:
Half a dozen all in one sleepsuits, and vests, a couple of hats and scratch mitts, a couple of cardigans and a snowsuit thing. You will get given piles of newborn and 0-3 stuff, and no matter what anyone tells you, you will want to buy some gender specific stuff once baby arrives, even it's only in the supermarket. If the birth goes well, you will be up and about within a couple of days. DD was born on Saturday, I was in hospital till Wednesday, and on Thursday we ran out of food so I went to Tesco's and spent an hour buying bread and milk and being congratulated by strangers.
Yes, little outfits are a faff, not as comfy for the baby and more work in washing, ironing blah blah blah but I am prepared to put money on every single one of us succumbing to at least a couple of teeny tiny outfits :-)
I bought loads of plain white cotton sleepsuits, and tie-dyed them in lovely bright colours. But then I'm just odd.
jazzcat vests go under their sleepsuits. It doesn't matter whether they are sleeveless or short or even long sleeves, choose according to the weather. Dress them in layers: vest, sleepsuits, cardigan, snowsuit or coat/blanket. You can always take a layer off or add another. I love baby clothes:-) my husband used to refer to the row of lovely sleepsuits hanging on the washing line by their toes as 'baby skins'.