Suggestion for a GPS module with helical/omnidirectional antenna
As far as commercial-off-the-shelf, SparkFun sells a helical antenna based receiver, also using the u-Blox chipset, the GS407 Helical GPS Receiver.  It's using a Sarantel SL1206 Antenna.  You may be able to find more antennas to your liking directly available from Sarantel.  Also, if you are eventually looking to embed this into a product, purchasing from SparkFun may prove to be more costly, so going directly from the manufacturer may save money.  One drawback to the SparkFun product is that it's limited to 4Hz update, according to the datasheet, and 2Hz according some of the comments on the product page.

If you are feeling more DIY, then you can check out this page of DIY GPS antennas.

If you are looking for more ideas, it might be worthwhile to purchase a few of the "runners watches" that are currently available on the market and see what they do.  I know that Garmin and the like manufacture these in pretty tightly-integrated packages, so they have approached the problem before.

Also, as an additional data point, I believe that the iPhone uses a patch antenna (I wouldn't imagine that there is much room for much else in there), and it seems to successfully track me when mounted on my arm during runs, so patch may be a viable option with some clever design.