I'm wanting to put on a sort of braai for my gf's birthday in june, but have no idea where to start in terms of food to cook etc. Want it to be a surprise and put in some effort so don't wanna ask her or her family straight.
So, best place for ideas / online shops / local shops (birmingham!)
Braais vary tremendously, but here's a few staple things that my Saffies usually insist on:
Beer. Ice-cold beer... or perhaps just somewhat chilled, as this is England and fairly cold already.
Double the quantity if SA are playing rugby on the day. Treble it if they're playing England!
Meat. Lots of meat!!

Boerewors is often a favourite with both SAs and especially Brits, as it's like a really tasty, fat Cumberland Sausage.
Sosaties (marinated chicken skewers, with sweet onions).
Steak, pork and/or lamb chops.
If you're going to an SA shop (see below), various seasonings, braai salts and so on are good. Might want to test a few out beforehand, though.
Snacks.
Best thing is to get some cream cheese and heavily drizzle a decent load of sweet chilli sauce over it. Serve as a dip with dipping crisps (ie not the thin Walkers type) or salty crackers.
Potato salad.
Obvious.
Bread and salad.
The usual kinds, ie rolls, baps, baguettes, French sticks, etc, but apparently this is something the females always take care of!
Pap en Sous.
Mieliepap (sort of like sweet corn porridge) and Sous (sort of onion/apple/tomato/garlic relish - Google a recipe).
Melktert.
Milk tart. Many recipes online. Usually served cold at our braais, so cook in advance.
Supplies:
None of the Brum SA shops seem to be online any more.
However, check around your local butchers, especially those who deal with a lot of game.
All things like biltong, boerewors, etc have to be made in the UK by law, apparently, so Cruga, Hunters and all the other main brands have set up shop here. But a savvy butcher will have cottoned on to this and many make their own, and/or contract to the big brands anyway.
Failing that, SA shops do tend to deliver nice and quick.
The imaginitively named 'The South African Shop' in Maidenhead is huge, very well stocked and very good.