Arnnworx sells a reasonably priced fuel pressure gauge.
The problem with others is that the fitting on the fuel rail is not a normal fitting that you will find on other fuel gauges, or in a kit by Actron or similar.
Here's a link:
http://www.arnnworx.com/catalog/index.php?main_page=product_info&cPath=65&products_id=279&zenid=0ffeb44223b537229c49f5d3de4bdbc5#.WebMyFuPKU k