Will 512MB RAM And 200GB Bandwidth Host 5 Low-key Websites

I'm seriously considering the LVPS-2 plan at SWVPS: 10GB space, 200GB bandwidth, 512MB RAM (burstable to 768MB). I have four sites hosted with MediaTemple but I want to give VPS another shot since it provides full root access. MediaTemple is hosting me fine, but I keep running into roadblocks with things that involve custom compiling. I'd really like some more flexibility.

So how easy would it be to add 4 domains to one VPS plan and have them all in their own subdirectory? Also, two of these domains would have one e-mail address, so I'd need a mail server along with a FTP server. I know these two to be slight resource hogs from my previous VPS experiences, as they both caused me to go over my limit (which was, I think, 256MB).

I sent SWVPS an email but all I got was a suggestion to get a dedicated server. These days it's hard to tell a genuine recommendation from someone trying to milk another $40/mo out of you. I really don't think I need a dedicated server for these sites, as I've hosted much more than that on shared servers (granted, that's a completely different area). I also can't afford dedicated hosting. This $20 price point for LVPS-2 is convenient, because it's the same price at MT, which I'm barely skimming by on.

Site #1 is a personal blog with one email account, powered by PHP and MySQL.

Site #2 is a company website and blog, powered by RoR, but not much database load. It would, however, run Subversion and browse it with Warehouse, a RoR SVN browser. This would probably be the main offender as everything SVN would be managed and run from here.

Site #3 is a software website in RoR, all downloads would be from Site #2's SVN server. It has forums, a bug tracker, a plugin/theme browser, and a development blog, and everything else is just (R)HTML.

Site #4 is another personal site, with one email account.