I use apache to host webpage, you could use IIS. Using sdk's to make html page you can change the resolution there. The default in the code is 320x240, but I experimented and changed it to 640x480 and that worked fine, so I expect it would work for you to any size you want, plus the embedded image can be run full size like admin says with a double click.
Your live server source will be the live broadcast option in the html shown in the sdk examples.
o.UseMediaServer ("IP/domain of media server"); \\I have my domain:5119 so I can broadcast anywhere
o.UseLiveAlias ("Your TV Capture card Alias");
I rarely use SMP or WMP for Umedia streams.