Talk Blogging

am I dreaming? I've recently discovered the joys of blogging. Now, after a couple of months of this, I find I'm dissatisfied with the templates you can chose from. I want a big 3 column blog, a big banner across the top, two fixed sidebars and a floating main column. Sounds easy enough but I'm having a hell of a time. I know a little html coding and designed my own website, so I'm no stranger to this but designing blogs is a whole different thing. It's XHTML, for one thing and they have a whole bunch of files, each one with a little code that you're supposed to figure out. Then, it seems, there is no standard way of doing this. Blogger has it's own code or something, as does WordPress, Moveable Type and a myriad of others.

Any ideas?