Get yourself a set of Surecatch "Big Game" pliers. The have a hook eye opener. Makes the job easy. They are adjustable so that you can only open them just enough to get the next hook through. No real need to heat the hooks.
http://########.com.au/index.cfm?pr=...product_id=563
I use Mustad 4200 for ganging as I prefer the straight eye rather than the turned back eye you get with the 4200D which come with pre-opened eyes.
Get the pliers! You'll love em!