I have found drums to be quite complicated for a straight up guitarist, or I would assume anyone who isn't a drummer. Luckily, I have been blessed with a shitty job that pays just below what people make from chapter 18 (or whatever) housing subsidies and welfare, so I've invested a lot of partial savings into my hobby (recording music). Free today is a lot better than it was even two years ago. Interfaces are not necessary (1/4" to 1/8" for instruments or usb) because ASIO4all does a decent job producing low latency direct ins. But I do prefer them; like my crappy Line 6 UX 2 24bit 44.1k interface (only reason I have is for my Blue microphones).
I'm not sure if you've ever gone to your local guitar shop and played on a Mesa Dual Rect, but it sound quite bland without a stomp pedal for additional gain to beef up its sound (both 6L6 and the other one). I haven't fucked around with a XXX or a 6505 sadly, but a TS 9 is (or something similar) is (I think) required to acquire a decent metal guitar tone. Same holds true with VSTs.
http://www.tseaudio.com/software.html has a great 64-bit TS 808 (based on Dunlap I believe) stomp pedal that works great for free. Their TSE X50 is based off the 6505 (I've still have better sound with Amplitube's 3 5150 model), but requires an impulse response to sound amazing (with minimal eq as long as its a humbucker in my experience [passive distortions].
I spent way to much money on headphones (about $300); only to find out headphones are garbage for mastering songs (I'm stationed overseas currently so when I recording the same track over and over for hours, I'm not pissing off my piss mates.. they're not a complete waste to me), and studio monitors may not always provide the best reference in an non engineered room. I've always found that you should master your tracks on something a lot of people have. Logic Speakers a great example. Other people burn me if you must, but Logic seems to hold a pretty good standard on computer sound interface (I use Logic's speakers in conjunction with my home theater, my car's sound system, and my Bose in ear phones).
For the money you are willing to spend, don't waste it on EZDrummer. Steven Slate's Drums if by far better, and requires much less effort. I own SSD and Superior Drummer 2.xx only to find out that I can't mix drums for shit. Steven Slate Drums was an epic downgrade, but the ease of quality kills any of ToonTrack's presets for Metal Foundry or the default Avatar (I don't have it installed SD2 default library). You lose a lot of control and dynamics, but its no issue if you know how to write your own drum midi.
I just recently switched back to W8 from OS X (Logic Pro), so I'm running a trial of Samplitube for recording. I have had a problem with 32-bit plug-ins, so it doesn't hurt to make sure your DAW, or your plugins are compatible.
http://youtu.be/qfh_ZkyZtwg consist of a long visual tutorial on how develop metal tracks. Although he specializes in Djent (and hes really hard to listen over a long period), this video serious listen under his description is a high valuble tool to learn how to develop, mix, and master metal tracks. Most of his conecepts remain true while you can do them with new and free plug-ins. Honestly I've never seen any video series more helpful. Just wish he would condense it.