The triple gives the lower gear ratios so I would go with that. It's always good to have some gears in reserve as the hills that feel fine after 30 miles feel a bit different after 100miles.
Triple chainsets are less common than they used to be as compact 50/30 chainsets have become more common. Of course it all come down to how well you climb,
I've never really seen the purpose of those calculators. If you aren't changing wheel size or crank length then all you need to calculate to compare is the ratio of number of teeth front:back. The lower the ratio, the easier the pedalling.
If you really want to bake your noodle, why no change the wide range cassette from the carbon bike to the Titanium one and you'll have an even better ratio. I'm assuming you have a chain whip, Cassette wrench and 5 minutes...
