... For example my plasma is 1366x768 but the options available were 1080i and 720p. 1080i filled the screen properly but the icons were so small as to be unusable. 720p left me with underscan (dark edges all around). I had to use something like 1388x775 to get it to fill the screen. ...
I've used CCC many times before as well, similar to your usage. Are you using an HDMI or DVI port with your plasma though? I'm curious as I didn't think you could force a custom res on an HDMI port with that utility but I could be wrong.
I use both a DVI to HDMI cable and a regular HDMI cable. The TV doesn't have any DVI or VGA connections on it so I can only connect through HDMI, component, s-video or composite. I chose HDMI over component because of the simplicity of one connection instead of 5.
I have both the HDMI and DVI to HDMI cables hooked up to the TV but only use the HDMI cable. I keep the DVI--> HDMI cable around because when I need to access the bios it doesn't show up when I connect through HDMI, I have to use the DVI-->HDMI cable.
That board is flaky as hell and I regret getting it but it definately will force a custom resolution using HDMI. The board in this barebones kit is based on the same chipset (690g) so I don't see why it wouldn't do the same.