There are a lot of books out with good
information on designing and testing patch (printed
circuit) antennas, particularly for data communications.
You can look at places like Amazon.com.
has a good list on RF Cafe where (he claims) the
ones listed are 4-star rating or above. Of course,
ratings can be slewed by biased reviewers, but in
general they are probably pretty reliable.
You should check them out. Most are around $120,
but get free shipping, and that's a small price
to pay for taking the guesswork out of your effort.