Dlink 624 wireless router: best external antenna replacement?

As per subject: I have seen two replacement antennas in local store: one is
9db(?) antenna on a stand with about 12-18" antenna and the other is about
the size of a pack of cards on what appears to be a swivel mount. Both are
designed to be attached with a cable about 1m perhaps?

Any recommendations to which one is best (or other choices?)

thx




Kerry Liles