Thinking about going either with a Wacom drawing tablet with Photoshop on the computer, or an iPad for sketching/drawing models. Industrial design student here. I see there are lots of pressure sensitive pens and such for the iPad... are there professional quality software and such? Obviously you can draw professional quality drawings with a Wacom tablet and Photoshop... it's just not portable and the whole concept of drawing something that appears on a different screen is tough to get over for me. If you could recommend a pen, which one would you guys recommend? And applications? Thank you very much guys!