Will the following be bright enough to use as a cove light? (240 lumens)
If not any other options?
It depends on whether you want to use the cove lighting for accent lighting or general.
If it is the latter, you could either double up the strips or use an alternative like the eW powercore lights. The Philips' website has helpful tips buried in the documentation which is really fairly generic for cove lighting.
Using any LED tape with a luman output of over 200 lumens is more than ample for good cove lighting.
I think I am going to stick with the LED light strips in my original post. 240 lumens per ft should be ample. The Phillips cove lights (eW cove QLX) are around 8x the price and put out the same light...