Camshaft dillema

The manufacturer has two spring types listed. One is a true dual spring with a dampener, one is a single spring with a dampener. I ask because the break in process for the new cam is different between the dual and single springs. Also because I wouldn't run the larger cam with the single springs.
There is no significant duration change by going with 1.6s. The ratio affects the rate of lift, because it's opening the valve further for the same given number of degrees of crankshaft rotation. Higher ratio also means the effective pressure of the springs is less because of the lost leverage. IMO - if the lifter went bad, you should check the pressures of the valve springs and if you want to go with 1.6s, replace the singles with the duals if you go bigger.

My advice based on the info given - go with the smaller one. Put it in at the recommended ICL. Run the 1.5 rockers. If you have dual springs - pull the inners for the cam break in process.

Advice based on your "wants" - run the bigger, replace the springs with duals (may mean machining the heads depending on what you have), and run the 1.6s. Pull the inners for the cam break in.