Depending upon the weight of your fixture, the hooks/clasps you can pick up in the jewelry section of Michael's could work well. They look a lot like the hooks in the first kit.
Whoops, forgot to add: I was in one of the more marine-centric fish shops in the Cincinnati area a couple weeks ago and saw several Coralife wire hanging kits for about $15. They may be worth considering if you can find them cheap enough.
Your local electrical supply warehouse/wholesaler will have similar items. They are used for suspending fluorescent light fixtures. If you go during non peak hours, they will help you out and generally sell retail.
The griplock systems are really well made. They supply directly to various light manufacturers like Columbia Lighting, so if you hunt for a Columbia distributor, you'll probably find they carry them (i.e. Columbia has their own part numbers for each griplock assembly).
I was at Home Depot last night and saw a bunch of different wire rope/grip/clamp options for super-cheap. Found them near the aluminum c-channel and not near the chains and such where one typically finds that thing.
May want to check them out. I didn't snap a pic but remember being impressed with the selection.