The patch seems like overkill if you're only having 5 cigs/day. The AHCPR says that there is not much research that's been done on light smokers using the patch (see AHCPR clinical guidelines ).
Scott Sledge, a physician at Wake Forest, says:

"Finally, those who smoke 5 or fewer cigarettes per day appear to have a low level of nicotine dependence and have few symptoms of withdrawal when they quit smoking. It is unclear if these patients benefit from nicotine replacement."

(See: An Introduction to Nicotine Replacement Therapy)

A google search on nicotine replacement for light smokers brings up mixed advice from medical sources - some advise against, others advise using the lowest possible dosage level.

If you do decide to try it, you might want to check to make sure you're not getting more nicotine from the low dose patch than you are from smoking -