Hello, this is my first post, thank you for any help you can offer!

Some background: I manage and host just over 20 WordPress websites on a managed VPS from a reputable hosting provider. The VPS has 1 GB ram and I believe it's powerful enough to host these sites (my host says so as well), they are generally low traffic in the overall scheme of things.

Checking the error_log file in public_html, I'm seeing many error entries, most go like this:
[16-May-2012 08:30:46] WordPress database error MySQL server has gone away for query SELECT.....and then it's related to a plugin or general WordPress functions.

I try to keep my plugin use to a minimum and the plugins I use are pretty standard. The other interesting thing is that I manage a couple other WordPress sites that are hosted on shared hosting with other companies, I'm not seeing these errors on those sites.

I'm pretty sure all these database errors are affecting the load speed and overall speed of these sites. I've done some research online and seen suggested fixes of modifying wp-db.php file, but this would be very inconvenient on 20+ sites and every WordPress update. I've contacted my host and they've adjusted some settings like max_user_connections and wait_timeout. Some of their final advice was "I think that consulting with a qualified DBA to optimize slow queries and the overall database performance would return better results."

It seems like hosting about 20 relatively low volume WordPress based sites should be manageable with a good VPS (and I'm open to upgrading the RAM or to their next level of hosting). Do I really need to hire a DBA or do you think I need to push my host more to help me?

I'll attach a screenshot showing some server statistics from the past 30 days.

Screen Shot 2012-05-17 at 11.54.16 AM.png
Screen Shot 2012-05-17 at 11.54.48 AM.png

Additional stats, but only 1 day time frame:
Screen Shot 2012-05-17 at 12.04.15 PM.png
Screen Shot 2012-05-17 at 12.04.26 PM.png