Welcome, and nice first question!!!
Others can chime in, but I would say do yourself a favor and get some paint strainer bags, then use the whole leaf hops. You can use pellets no problem if that's what you have. Typically I think you use 15% more for leaf in order to get the same than from pellets which give you better efficiency. It also kind of depends on your setup. Cons for both are that pellets will gunk up a screen, but end up losing less wort in the end. That's why I say if you want to use leaf hops, try the paint strainer bags. Best of both worlds. If you don't try to separate the gargantuan amount of hops you will be adding for an ipa, prepare to lose up to a gallon of wort out of a 5 gallon batch.
So for every oz of pellet hops, use 1.15 oz leaf. Cheers!