Effects unit wise, if you want a floor unit I'd say go for a boss gt-5, get one second hand as they aren't too expensive. They have a host of features that can be had for not much money. Oh, and they are pretty indestructable. Metal casings are a good thing. The manual is a bit crap if you want to do an midi-control with it, but once you've figured it out for yourself it's quite simple. But go out and try stuff out, just never buy anything plastic (or by zoom, I used to own a 4040. I sounded ok but lasted 3 gigs...).
If you are planning to go to a full rack setup, then I'd sayt get an effects unit from TC Electronics. Fantastic stuff, sounds amazing and transparent.
As far as amp setup goes, you can go two ways. Either a head or a seperate rack mount preamp and power amp. A single head is generally less expensive, and in most cases will seve you well. If you want a nice high gain head that gives you full distortion with tubes and are on a budget, then get a peavey 5150. Nice amps, tons of gain. If you have money go mesa-boogie (which is damn expensive, but worth it). Both of them are very american sounding amps, but have tight power stages which is nice if you want all noise to die quickly. Marshalls are nice as well, but I haven't heard anything properly since the jcm900 series. Last sound I liked was the jcm800, the new stuff doesn't do it for me...
Rack setups are weirder. They generally work out a lot more expensive as well. And by a lot, I mean a lot. But hey, if you've got cash to burn and want a really nice tight focused high gain sound with great tone then get a mesa-boogie triaxis with a mesa simul 2:90 poweramp. Awesome combination and louder than hell
, then again, this setup will set you back the price of a small car pretty much
Basically amp wise, the best thing to do is to take your guitar down to a store that has a good selection of amps, plug in and go for the one that sounds best to you. Although getting a trixis will solve all your worries about good sound (and if you get one, read the manual....)
Cabinet wise I'd say marshall always is the safe bet, they are pretty much a standard. But cabinets and speakers do contribute a lot to your sound. But for straight ahead metal, a marshall cab should do you fine. They can also be got second hand for a decent price (no point buying them new to be honest). Then again, if you can afford a mesa cab...
Hope this helps...
