I am in a metal band and about five months ago I got my first decent amp, a ValveKing 212. Now I am at the point were I am ready to invest in a better guitar (I still have my starter one)

The one that I have been mainly been looking at is an Ibanez S320 but before rushing into anything, I want some opinions on any guitars suitable for metal for around the same price. I don't want to spend over £400 if I can help it.

Yeah, for the mid-range, Ibanez is probably the best, in my opinion. Better yet, it might be a good idea to go USED and get a little better one for the same price. Look for a Japanese Ibanez on ebay or something. You can get a good RG japan for around 400-500 dollars.

I know a lot of esp fanboys will say LTD is better, but blah. But, LTD does come with some cooler shapes and sometimes with some EMG pickups which is really what you want for metal.
The ESP LTD JH200, the pups aren't that bad, I've had it for a long while now, and its better than the majority of guitars I've played (including several £1000+ guitars).
Just look out for the 200 series ESP guitars, they are really good, and you can just change the pickups out for whatever you want...

But, the Ibanez S series is bad if looking used, they keep their prices but aren't as much new, and then the RG, so much more expensive new, they half their prices used, I swear. Look out for an RG550, I heard they are good and I saw one on Ebay for liek t3h n0t br00tz amount of £400... srs face....
Mmm lets get some basic specs down and shit.

What type of bridge?
What type of neck joint?
What pickup layout?
What type of pickups?
What woods?
Anything else?

Aside from that the S470 model I played was amazing for the price (if you're not paying in aussie dollars that is) the neck well I dislike most Ibanez necks but the guitar was really solid.