Don’t want to advertise another company product on this site, but NavSpark has a ''feeler" product on Indegogo for USB, Arduino GPS boards at:
http://www.indiegogo.com/projects/navsp … s-receiver
These have the S1315-RAW chips on one option at a rather good price. And they include a fast Arduino porcessor that might have room for some fast math before going off board. Good enough that SFE could re-sell at a profit and still keep us happy. Hopes it makes it’s funding!
N0UU