MediaLayer would be able to handle this easily but they're not based in the UK. As for a VPS, I would probably look at higher performance shared hosting plans rather than a VPS. You'll find that a shared hosting environment geared towards hosting more intensive sites gives you a lot more room for bursting.
In my view you have still 3 options to go :-
1) Go for a Big Shared hosting plan : but if your website eat more CPU Host can click you.
2) increase your budget a bit and go for a Semi-dedicated server, you will get good resources and more CPU time then normal shared hosting.
3) VPS Hosting- can also work for you; but you have to mange most the stuff by yourself like VPS management, backups etc.
__________________Gineey - JodoHost.com
Windows VPS, HSphere Reseller, ASP.NET, ColdFusion
Shared hosting should still be able to support your requirements. It would also be worth implementing the word press caching mod to reduce the amount of CPU used when you get visitors on the site.
Hope that helps,
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