That's a totally different question. If wildlife is even part of the equation, 200 isn't long enough. You'd need to add at least a 1.4x TC to it to get even close. So in less-than-ideal lighting your 70-300 IS (either one) will be vastly superior to the 70-200 f/4 +TC, since you'll be able to use a slower speed. At the short end, things get a little fuzzier,since the shorter focal length means you can use slower shutter speeds, and the L advantage will be able to come through much better. So the quality advantage really depends on what focal lengths you'll be using most of the time.
If you're considering the 70-200 f/4 vs the new 70-300 IS that Canon introduced last fall, you'd need to add the cost of a 1.4x TC to the equation IMHO, so if you're on a budget, make it the 70-300 unless you don't, ever shoot long. If you were thinking of the (very compact) 70-300 DO IS and included the TC in the equation, the costs would be about comparable. There I might decide on bag impact (which would I prefer to carry around all week while travelling,if that matters).