No need to change pushrods with any of your above choices. I would change to a double roller if you're getting an XP cam so to answer that question, yes. Also machined oil pump cover, double roller timing chain (again, people have run a single with the XP, but it's not recommended) and better springs. Like 130# springs. Plus a tune and whatever else you normally need for cam install.
I see you're a fairly new member? A lot of things can go wrong with a cam install so if you're not a pretty competent mechanic, or aren't going to pay someone else to do it, so you might consider steering clear of the Cam.
An intercooler like you mention in the OP isn't a bad idea. If done correctly its easier than a cam and can be very reliable. Sealing it is where people mess up.
Do more research, ask more question here before jumping into something.
And With a Cam, Headers and E85 I could only run a 3.0 pulley with no knock. Off of e85 I can do a 3.25, but still see knock occasionally (pretty rarely, but it pops up now and again).
