Have a read on the relevant threads on here.
I started with a Turnigy 9x TX / KK2 board and a Hobbyking 330 clone. You may want to get the 450 size frame though as it's more suitable for lifting a GoPro.
Get the 'Afro' esc's if you can from Hobbyking too (30 amp versions) and some 'Sunnysky' motors (980KV 2212) from Banggood.com.
Motors I have had from Hoobyking are questionable in terms of Quality - Sunnysky are fantastic.
3S lipos - around 3000mah and you are pretty much set
If you want to make is flyable for a complete idiot - get the Naza Lite from quadcopters.co.uk as they are on offer for around £109.
My Fav Quad is my little wooden one with a KK2 and Sunnysky motors, it's a missile. Naza Flight Controllers are very 'soft' and 'safe'. Ideal for ariel video, but not for really learning how to fly and do tricks. That's when it gets expensive....