This one's easy for me.
PRS Custom 24, 10 top, bird inlays. Preferably Black Cherry, or vintage yellow with zebra bobbin pickups. That should cost about £1500-£2000 from a private Ebay seller. I would have course collect it. I've been so close to buying one so many times, and i would have gone for it if they'd taken my PRS CE24 as part-ex.
I'd buy a Fender Iron Maiden signature strat, or a US Fender Strat special (the Floyd Rose one) in vintatge white. That should be about £600 ish, unless i can find brand new ones. I would buy more Strats, but i already have two Japanese ones, which are awesome.
Peavey 5150 2x12 combo £600 maybe?
Boss GT-8 £220 ish. I used to have the GT-6, but i replaced it with a Pod XT live. In some ways, i wish i'd waited for the GT-8 to surface. I don't really care about rack mounted effects.
Marshall Stack. Probably a JCM 800 head for that classic 80s metal sound. No idea what that would cost, as i've never looked.
I'd also get some stand alone pedals.
Boss MT-2 Metal zone
Boss Super overdrive
Boss digital delay
Boss chorus
MXR Distortion
MXR Phaser
Ibanez Tube Screamer
a good tuner
If there's enough left, i'd buy one of the Ibanez RGs with the double edge bridge. An RG2020 maybe.