Need advise on a good cinema system

Hoping somebody will be able to help me out with a purchase I intend to make in the next few weeks.

At the moment in my house I have:
42" LG LCD HD READY TV (bought it 18 months ago)
X-BOX 360 with an X-BOX HD DVD DRIVE (have a good few HD DVD movies)
WHARFDALE HDMI DVD PLAYER.

In addition I am about to buy a FREESAT HD RECIEVER (so I can get all the free sat channels and BBC/ITV HD.

I was planning to go onto the richersounds website and buy a really good home cinema system. Im looking for one that would have HDMI outputs so I could connect the X-BOX, DVD Player and HD Receiver into and in turn connect the cinema system to the tv. What system could you recomend? Should I get an all in one system or is seperates the way to go? I have a budget of 1000 euro to spend on it.

Also I am toying with the idea of getting a new 1080p LCD TV. At least a 42" size. How much difference in picture would I get on an 1080p LCD TV compared to the tv I have now? What tv would you recomend? Any Samsung models I have seen in the shops seem to have a fantastic picture. Would they be a good model to go with.

If I was to get the tv with the cinema system I would have a budget of 2000 euro max. Id really appreciate any advice you could give me. I want to have the perfect entertainment system and want to get the right equipment for it.

Sorry for all the questions but this purchase is a treat to myself as I have been saving up for this for a good while and want to make sure I get it right.

Thanks

Gazzer