Creating a set of filters - your experiences and advice required!

My lens collection is complete for the foreseeable future (my wallet says so) so I'm in a position where I can devise a filter set which covers as many of the lenses as possible. I don't know a great deal about filters at all so all of your advice would be appreciated.

My lenses are:

7-14mm, 14mm, Pan 14-42mm, 20mm, Oly 45mm, 45-150

giving me filter threads of

37mm x1

46mm x2

52mm x2

I currently have the following screw-in filters, which may or may not be of any use:

No-name 46mm UV

No-name 46mm CPL

No-name 49mm 1A Skylight

No-name 52mm CPL

Hoya 55mm 1B Skylight

Hoya 62mm 1B Skylight

No-name 67mm CPL

49-52mm step-up ring.

I've listed all of the sizes for the sake of completeness rather than because I imagine they'll be of any use, but I suppose it's quite possible someone will have a novel idea to make use of them.

I'm looking for a solution which allows as little duplication as possible and includes a polariser, NDs and ND grads. My budget is low, but not at a large expense of IQ - one of my polarisers adds a distinct cast.

Does anyone have any recommendations for a suitable system?

Thanks!

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