I don't know what spec CPU you have (you don;t say in that list), so no idea what would actually represent an upgrade. It's also not clear what you want your PC to do.
In practice if you are upping the motherboard / CPU combo, your RAM will also need to be changed. Rarely do these match up as the technologies change, if you reuse it might work, but often with reduced performance. That means your £200 budget could be quite restrictive.
For some ideas, many suppliers do bundle deals. At least you know the components are matched:
http://www.overclockers.co.uk/produc...833&catid=2836
http://3xs.scan.co.uk/custom/profess...locked-bundles