Not to worry! Kenko makes great lenses. All you need is a step-up ring. This is just a double threaded ring that allows you to attach that 37mm Kenko lens to your 30mm camera lens. Since you're stepping up in size you shouldn't have any vingetting problem. (That's where the camera doesn't see all the way out the wide angle lens and picks up a bit of the inside of it. This results in black corners in the video picture.) Step-up rings are usually less than $10.
Go with the Kenko lens - they work great.. Get a step up ring as previously stated.. I use a .5 on my PC5 - the .42 was a bit too large for my liking.. The difference in picture is not much, but the lens is physically quite a bit larger..