Just a quick thought for now, but if you are looking for a surround sound system that is not going to be used for music, then bookshelf speakers on low stands are probably your best choice. But get bookshelf speakers, NOT tiny satellite speakers; at least, that's my opinion.
Since you will be using the bookshelf with a Sub, the ultra low of a floorstander aren't of much value to you. I personally always prefer floorstanders, but with your height requirement, there are few out there that are going to meet your needs.
Of course, if you find a bookshelf speaker you like, then before you buy, you must search for a stand that gives you the proper clearance from your TV. Stands usually come in a variety of sizes, so that shouldn't be a problem.
In AV amps/Receivers, I would say don't go less than £400, unless you can find a real deal. I think right now there are a Onkyo 607 and a Yamaha that were recently £399, that have been reduced to about £350 or less. That's a good deal. (SuperFi.co.uk and others)
For speakers, if you jump right now, you can probably pull together a Diamond 9.1 system. I think i recently calculated the components at about £430 for a full 5.1 set form AVbristol.co.uk. You can do it cheaper, if you buy at 'best price' locations, but that means buying the full 5.1 system from three or four sources. AVBristol.co.uk can help you pull together a nice system at a good price.
That adds up to roughly £800 for amp and speakers.
In PC World, in the latest issue, they tested a range of BluRay players, and used the PS3 as the standard to compare all the others to. In the end a very low cost Panasonic came out on top, and the PS3 came out in the middle. So, for now, it is a decent BluRay player, and I would leave the BluRay as an upgrade for later if you feel you need it.
Speaker stands are about £50 to £75 per pair. Then you need decent, but not great, speakers wire, and mid-priced quality interconnecting cables. Some of which you might already have.
So, it seems you should be able to arrange a nice system within your budget range.
Steve/bluewizard