Ttsx ought to be fine.. just put it where it matters.The big ole heavy bullets were fine back in the old days when penetration with the ligher ones not good, but any of the three above will penetrate all you're likely to need. Last year I hit a Kudu, at 275 Yds, using the 150gr Ttsx in a 308, and it penetrated from the right front shoulder, back through the Kudu and came out his side, through the paunch..can't need more than that.
Quite a few of the younger, up-and-coming PHs are starting to think like this. During my research, I noticed most of the more experienced guys are still recommending heavy lead bullets based on their formative years' experience, while the younger guys are seeing the benefits of lighter, monolithic bullets during theirs and are recommending them. I figure neither is a wrong answer as the PHs of the era are merely reporting thier observations at the time.