I personally prefer rapid front-end frameworks like bootstrap, foundation, etc.
Mockup with Photoshop (or paint*net/GIMP), convert to vector with Illustrator (or inkscape), then put those shiny graphics to use in a stupid-simple framework like the above-mentioned ones.
If you're planning on using WP for your CMS, bootstrap and foundation have a ton of "blank" framework themes so it's pretty much as easy as dropping your CSS file in the theme and BAM....wordpress ready.