A Couple (OS/programming) Questions ...

My dear dA friends, it seems I am currently facing a dilemma finding a suitable Java development environment. My only viable work computer is a Mac running OS X 10.6.8. Our class is going to be working with Java Development Kit 7, which is only available for OS X 10.7 and up. I've already attempted to shoehorn JDK 7 onto OS X 10.6.8 using these instructions; I followed everything to the letter (complete with using the JDK 7 version specified in the post) and it still didn't work. (I didn't press the point further because I was concerned about screwing up JDK 6, currently installed.)

Right now I'm faced with this set of options:

1. Upgrade to OS X 10.7 and risk losing my rather impressive software investment in OS X 10.6 (the thought of losing Photoshop alone makes me want to cry); 
   
2. Partition my drive and dual-boot with Windows or some JDK 7-supported flavor of Linux or Unix and be faced with having to reboot constantly to switch between tasks;
   
3. Install JDK 7 on a Linux/Unix/Windows virtual machine and risk poor performance / completely decimating my system resources, or;
   
4. Attempt to work on my Windows 7 laptop and not get anything done, because I loathe using that computer (it's about as loud and vibrate-y as a blender and has a really, really bad screen) ... OR: 
5. LIVING DANGEROUSLY BONUS OPTION — The textbook we're using proclaims that most of the lessons and examples are compatible with JDK 6, so just use that until I run into work that requires the use of JDK 7, at which point I decide between options 1 — 4. 
   

Of the options I'm leaning most toward #3, simply because it requires the least amount of risk and monetary/time investment. But I'm wondering if any of my (undoubtedly smarter) friends / watchers have advice because they're all on the table at the moment. 

As for potential OSes to use — I've been kind of out of the Linux/Unix/thingsthataren'tspecificallyOSXorWindows game for awhile (not on my own volition, mind you), does anyone more knowledgable in this particular area have any suggestions? If I'm going to be running it in a VM, I'd rather use an OS with a small resource footprint. The only other requirement is that it can run JDK 7.