http://bobtheveg.dyndns.org/SRO/Char_Build_Applet/
use that, put in how much int + str you have as lvl 19. then, go pure int until lvl 70 ish. If at that time, you're int balance is 80% or higher, then yes, you can be a hybrid. If not, then it's probably too late for you to add int.
edit: I was bored, so I did it for you. At lvl 70, assuming you added pure int after lvl 19, you would have 64% phys, 78% int. It's too late for you to be int hybrid, unless you really really want to. It will be hard to lvl, and you won't get the benefits of being int hybrid until lvl 80 or so.