Just wanted to put my input out there. I have a macbook pro laptop. I don't use a mouse because I like the trackpad. That being said, you can set up the mouse to right click. Because I do not have a mouse, I can only guess, but I think you can set it up to two-finger click for right clicking. Basically, instead of using one finger to click, you use two at the same time and the right menus should come up. I'm pretty sure you'll have to go up to the Apple icon in the top left corn and select System Preferences. Then go to Mouse and change settings. Because I do not have a mouse connected to my computer, I can't access the menu options, but just mess around with it and you'll get it.
Also, did you know that you can duel boot operating systems? You'll have to fork over the cash for both the Windows system and then a duel booter program like VMWare Fusion 3 ($80 on apple.com). If it were me, I would also consider upgrading the RAM to 8gb and even install 1TB or better hard drive. That's just me though. I use up a lot of memory in the crap I do.
Also, Lion is the newest Mac os. I have Snow Leopard which is one behind. There are few differences but you will get Lion or better (depending on when you get a new computer).
As for programs, if you have an ipod or even download a lot of music (especially P2P, which is illegal and blah blah blah lecture), then I would suggest getting TuneUp. It is an iTunes side-along that will organize your music for you and pull album covers as needed. It comes in handy when you have 2300+ songs.
Also, an anti-virus is always good to have. I have two: IAntivirus (which is free) and then Mac Keeper's built in one. Which brings me to Mac Keeper. This program is a paid-for cleaner that scans your system for invalids. It also has an anti-theft program that tracks your computer if stolen as soon as it goes online. You have to register for an account and I haven't done it yet, but it should be pretty straightforward. It has a data encryptor, Undelete to retrieve lost files, a shredder to completely delete something, a backup program (though if you buy a time machine external drive, you can do the same thing there), something called ZeoDisk that hasn't been released yet so I can't say what that is, a duplicates finder, a Files Finder which I never use because the spotlight does it just fine, a disk usage monitor, a "wise" uninstaller which I've never used, and user support. It comes in handy.
There is also Facetime and Boom. Facetime may not be Windows compatible, but I'm not sure. It's great for video calls. I don't use it much though because I have my iPhone. Boom is a cheap ($10) program that bypasses your computer's natural sound settings to increase volume. It comes in handy for us hard of hearing people listening to audio with lower maximum settings. I love it when I'm listening to the podcast Twilight Series Theories or Netflix. The sound in general is okay for everything else.
If you have any other questions, just shoot me a PM and I could probably answer it.