If you want to dual box with your Hunter + another toon, quest 1-10/15 then instance grind with your Hunter as high as you can. 60 hunter should still be able to chew up SM so you can probably get to 40+ within a day+- /played or so depending how efficient you are. Then quest, using your hunter to kill everything.

If you want to duo 2 toons up then questing is probably your best bet.