Hybrid Shafts

Hi all My Used Golf,Just bought myself a Bobby Jones 19 deg Hybrid from ebay.it has a stock stiff shaft in it Golf Reviews Now, JS7 by graphite design.I would like to change the shaft in it Golf Drivers Blog, I have an Accra HF M4 Stiff and an Irod Tour Hybid utility shaft cb100 stiff at home to use. only thing is I think the accra will be half inch short.should I use the accra with an extension or the irod? or should I even try a steel shaft like my irons?cheers