Well I've a bit of the same equipment and am just making a transfer.
What I like to do is get a transparent the deals well with a different kinds of boosters, overdrive and distortion pedals. Something a Legacy does really well imo, it is just waiting to be boosted with your favorite flavor. Usually these amps also deal well with the kind of guitar and pickups you run into it. That is: respecting their characteristics.
Atm the moment I own a Legacy, Marshalls DSL50 and 6100LM which I'm toying around with to see what I like most, but they suit my above expectancies well. From demo's a think an alchemist would fit in here as well, and I guess the JVM as well. But they all have their own kind of "base tones" clean and lead if you will, where you further can build upon. Now this base is about personal preference. the Legacy's clean is unmatched really, very harmonic warm en rich, but the lead is a bit too spongy for me and I like the tighter denser lead of the DSL, but it's a bit colder... so you see, you have to test en hear yourself. I personally buy everything used, test around and resell/trade for something else. I'm afraid it's the only and affordable way
Further I use loose pedals for the boosting part (I have 3 Rats, tubescreamer, SD-1 that awaits a mod, a Satchurator, etc), to play with the amp's base tone. A most valuable tool for toneshaping is a graphical EQ. Really, get one, this can make all the difference in the world. I use the amp's EQ to set a basis, and en EQ in the loop the define what I want, but the difference can be huge.
I just put a DD-3 (1st version btw) and 10 band MXR EQ on sale. They both do perform well, np, but I really prefer to have a few EQ settings at hand, also since I use different booster, each booster can work better with it's own 10 band EQ setting, same goes for guitars and pickups. (my Washburn N4 has such a specific tone, that it does not work on setting of an Ibanez RG). So I want to get the GT-10 (I have to pick it up this afternoon actually because it gives me that graphics EQ stuff, and probably a more than decent delay. I'm planning to use it only for it's fx, preferable in the loop fot just these base fx. A flanger/chorus/compressor once in a while for fun (can't justify owning these as loose pedals just for the one time I use them). It's also good to have a tuner in the GT-10. My TU-2 works fine for tuning but it sucks tone. My lead channels loose some bite, so I can't stand it having it in my chain. I hope the GT-10 doesn't suck too much lol
but I've read good things about it.
I really digg Nuno Bettencourt tone btw, so that's a Rat2, a GT8 in a DSL and done.
Further if you mention 1000£ for the amp, go used, and get a head and a cab. Combo's are back-breakers as for as portability goes, can have overheating problems and are not tube-friendly at all. The Legacy combo I had sounded like a rattling cage, totally no issue with any head I had.
Hope this helps a little.