#1
okay i'm lookin for a replacement for my jackson dinky as its gettin on a bit now.
lookin to spend around £300 to 400 mark.

so far i have narrowed it down to these

http://www.thomann.de/gb/ibanez_rgr320exrbk.htm

http://www.thomann.de/gb/ibanez_s320_wk.htm

http://www.thomann.de/gb/ibanez_mtm2_bk.htm

possibly a sz aswell. possibly go a bit higher on price if you can recommend something good.
must have a slim neck and versatile aswell,even though i mainly play rock/metal.
#2
The s series has a better bridge than the other two. It's better for metal and rock.
Another good one is the ibanez rg1570. It's good for soloing but basswood doesn't have too good bass. It also has more mids than the s and is a more versatile with the single coil.

The best thing to do is try out guitars until you find one that suits you best.