Easiest/Cheapest way to a 4bbl 318?

So assuming I go with the "302" heads and follow T67Power's advice (look for the long post on pg 2 http://www.forabodiesonly.com/mopar/showthread.php?t=115938&page=2). Will I need to change the size of the intake or exhaust valves from the stock size? I've read a couple of times about people recommending 1.88 intake valves (or larger) and I was just wondering how much of a difference this would make. What about the exhaust valves?

How much would this add to the cost of using these heads?

And before you tell me to go get a set of 360 Magnum heads, I have already decided against it :)