seat belt Harnesses and kids seats

I have been trying to decide as well which belt to use when I secure a kids seat in my convertible. I have seen alot of the 4pt harnesses on Ebay and most of them look very cheap. After alot of research, I think Im going to try the one listed below. They come in 8 different colors and 2 different buckle options. Ill let you know how it works out.

Heres the link:

http://wescoperformance.stores.yahoo.net/am4point.html