Circular Polarizer - you can't put back in Photoshop what's not captured. If you capture a bunch of white glare reflecting off water, you can't PS back-in the image behind the glare.

Graduated ND filter - external Cokin mount so split can be placed where needed. Again, blown highlights can only be brought to lighter shades of gray in PS. Shots with different exposures can be merged in PS, but only with fully static scenes.

ND filters - 3 stop - to get slow exposure speeds in bright light - waterfalls, etc.

That's all I carry.


Regarding lenses, I'd go with the 2.8 versions of those you listed and the 1.4TC. The 2xTC causes too much image degradation. If you need something longer, look at a 100-400L.

2.8 is fast, but look at primes for really low light - 85 (1.8 or 1.2), 50 (1.8, 1.4 or 1.2) and a short one (24/1.4, 35/2.4)