Pretty much any one you choose from ebuyer, as long as it's Socket1156 (supports i5, sometimes i7 processors - you need to check each one you're interested in, prefferably on the manufacturer's site), and has ATX format. That's all you need to have to avoid incompatibility. You can go for Micro ATX, but it sort of defeats the purpose of getting a larger case.(your case is of the ATX format, right?)
You can also check how much memory you can fit in there, but that should be 8+ GB for most new(e.g.those supporting i7 processors) MBs anyway.
All the additional features are just the icing on the cake, and are of secondary importance. You can look for a MB with a good soundcard on board, or a large number of USB ports if it suits your fancy.
If you'd like to put off buying a graphics card, then look for a MB with some integrated graphics chipset, which should let you play less-demanding games.
If you're going to buy a GPU anyway, then don't waste your money on a MB with a fancy graphics card integrated.
Also, as malimbar04 said, you could refine your search by manufacturer, but I'm not very much knowledgeable about those. As a rule of thumb, the more popular, the more trustworthy.
Here's an example for a 100 quid, with integrated 8 channel sound card, up to 16GB RAM, and crossfire support, even though I doubt you'll ever feel a need to use two graphics cards.
http://www.ebuyer.com/product/191224It does not come with any integrated GPU, as far as I can see.
This one is a few quid cheaper, but only allows i5 processors.
http://www.ebuyer.com/product/172655You can spend more on your MB, but keep in mind that the bulk of the price will go into features that you'll probably never use, and/or integrated GPU, which will be completely redundant, if you're getting a dedicated card anyway.
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