A few thoughts, suggestions, and questions:

Thoughts
First...Most sites are either targeted at 800*600 or 1024*768 screen resolutions with the growing number seemingly moving toward the latter. Since you said your site looks terrible at 1024*768 this presents you with a real problem because a lot of folks are going to be using that resolution on their monitors.

Secondly...there are sites that use a liquid layout that attempt to address differing screen resolutions but I have found that this approach was either too much work or limited creativity.  This is just my opinion and my experience as I am by no means an expert at layouts.

Suggestions
First...I would target either the 800*600 or 1024*768 depending on which one is going to present the least issues to you at this point.  This could be a lot  of rework depending on your present graphical elements, content, # of columns, etc. The work could also be made harder or easier depending on how you developed your skin, meaning did you seperate your design from your html structure.  If all layout elements are controlled via css, making changes could be easier.

Secondly...I learned this the hard way myself developing on a widescreen laptop.  When you develop your skin you must not only consider browser compatibility and screen resolutions but also monitor types such as widescreen laptops and standard square monitors.  Monitor shapes and size differences don't seem to affect layouts so much as they affect graphical elements.  A header may look fine in a 15.4" laptop screen but look "big" in a standard square monitor.  As an example, I developed on an Acer widescreen laptop but all my users were viewing the site using a 17" DELL Flatscreen (not widescreen).  On the DELL monitors, all my graphics looked "stretched."  I had to rework each element until I was comfortable with the visual appeal on both monitors. So, the suggestion is to test the skin on both types of monitors during the development process.

Third...you could consider purchasing a skin that would closely match your layout structure for content and make graphical modifications to it  to fit your needs.  This could possibly be easier than a rework of your current skin.

Questions
Is the site viewable or live?  Could the community have a look at it to make suggestions?

Paul

Nice work so far.  The site looks best at 1152*864 but this is probably the wrong resolution to target for your specific audience.  You should be able to adjust your layout for 1024*768 without too many issues.  You will have to resize some graphics but thankfully it doesn't look like you're too far down the road and a rework should not be too difficult. 

The gray background presents you with the same challenge I had when I was first developing my site

www.jupiterchristian.org

When using the background space around my layout, it fit and looked fine at 1024*768 but when viewed at 800*600 the user, already forced to scroll horizontally, would be forced to scroll some more just to get to the first part of the content. Some folks will use a background image or color like this and set their inner page (all content) to a size of 800*600 so that those viewing at 800* 600 just get the main layout without the background.  Then if they view the site at a higher resolution, they will see a centered page with the background. I tried this approach but I had too much content to publish and an 800*600 content page felt too crowded. I finally decided to target 1024*768 with no background space.  So, my site fills the screen at this resolution and at 800*600 gives the end user as much content to the left as I can before they are forced to scroll horizontally.  At higher resolutions - 1152*864 and above, the site centers and just shows a white background.

My only suggestion at this point is to target the 1024* 768 screen resolution.  The amount of content you will end up publishing for this site would be a challenge at a lower screen resolution.  Anything higher than 1024*768 will cause you to miss your target audience.

Paul