If you want customised graphics but don't want to draw your own, look at software that renders images. For example, Blender, Poser, Daz and Iclone are all 3D applications that can render a 2D graphic.
You place the 3D object in the scene, select render (which in this instance is the process of creating a 2D image from a 3D scene) and you have professional looking graphics.
Check out Renderosity. They have a large free section (make sure the items allow commercial use). Daz is free but doesn't include much content. You pay for Poser (available at Renderosity) but Poser includes a huge graphics library and animations which you can apply and render. You can customise the 3D graphics which lets you make your game unique.
You can see some videos and screenshots on my website. I used Poser to render the graphics (most of the graphics I bought at Renderosity and customised them).
There's still a learning curve - I've been playing around with 3D graphics for years, and am also a minor vendor at Renderosity, but it's quicker than drawing everything.