Neither of those sticks are particularly well built out of the gate, but the Tekken stick is the worse of the two. If you're not interested in a TE stick (which has high quality Sanwa parts right out of the box), I'd go with the SFIV stick. It'll work on your PC plug and play style and is the least shady of the two.
Honestly though? If you have the extra scratch and do a little online browsing you can find a TE stick for a hundred bucks or less and it's a far better stick than the standard Madcatz stick.