Hey, I have been playing acoustic guitar for about two years now and I'm not entirely sure on which electric to buy.

I play Alternative Rock mostly and I'm in the price range of around £200-£550

I was thinking about getting a Epiphone Les Paul custom but I'm not sure, anybody have any advice on what guitar to get? I want something with a nice sound and that will last me for a long time.

Thanks, Will
Most guitars will last forever, so durability is out of the question. I'd say just get a Mexican HSS Stratocaster or an Epiphone Les Paul in you price range. Try out both. They are very generic, but are totally different in tone, feel, and looks. See which you like better, buy it, and your next guitar(s) can have similar specs.
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Mesa/Boogie DC-3
Johnson JT50 Mirage
Ibanez TS-9
Morley Bad Horsie 2
Boss CE-5

ISP Decimator
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Quote by Paranoia-Will
If iI go for the epiphone Les Paul should I go for a Custom or a Standard?

Which ever you like the look of.
You need to find a good shop and go and play a few to see what you like. That way you will know when you find the right guitar for you.