If we're looking at a QB the Cards will draft, the first thing to look at is whether they are a fit for Arians offense. The guy is going to have to be a pocket passer first. Look at Arians history, he's had Manning, Ben, Luck, and now Palmer. Ben and Luck have mobility but they are pocket passers first and can beat a team from the pocket.
I don't think guy's like Manziel, Mariota, and other spread offense QB's fit his style of QB. The guy's that fit his style are Carr, Murray, Morris, Bridgewater, Hundley, McCarron, Mettenberg, and to a lesser extent Boyd. I'd bet Arians and Tom Moore have little interest in dual threat QB's.
Out of the group I listed, I think Hundley is probably the best fit. He flings it downfield and is a passer first, yet has the mobility to escape the rush.