I can't suggest any of what you asked but have an alternative idea for you that I am using.

Install a full size filter in a cabinet above / beside the fridge and hook the fridge up to that. My concerns about the fridge filters are the size, level and price. The one that comes with my fridge can block 5 or large micron particles, removes some bio contaminants and has to replaced every 3 months at $35 a piece. The replacement can last up to a year, costs $32 for a replacement, can remove 1 micron or larger particles and removes most bio contaminants. It has been about a year since we looked at the alternatives but I just don't fridge filters are practical. I see them more as a reoccuring money stream for the fridge makers.

Do you have the model number of the fridge filter you need? The best way to find the best price is to type the model number into google and see what prices come up the cheapest, including those sites that are offering free shipping. Also, a lot of sites selling fridge filters give cheaper pricing if you buy 4 or more at a time.