Can you recommend a system for filtering residential municipal water?

Okay. I'm sorry. You have so many filters, I get very confused. I'm hoping you can help me. I am looking for a stainless filtration system. I presently have a Cousen's (I think) under the counter system constructed of plastic. I recently read that the plastic could possibly leach and that the BEST filters are stainless. Would you agree??? Our family of five consumes mass quantities of water...far more than just a few gallons daily when considering the tea pot, cooking, etc. Can you recommend a system for filtering residential municipal water? Though I would love a "whole house" system, I am presently only able to purchase a "drinking" filter. I was looking at the stainless IS100UC and then the IP100UC and couldn't quite grasp the difference. And then of course, there's The Sovereign...which sounds like what I'd love but can't quite afford. Which would best set my mind at ease for filtering all the yuck that the city adds (chemicals etc.) plus everything that leaches in, as well as all the natural metals and bacterias??? Yikes. Again, reiterating: I want the best you have to offer. And could you compare any of them that you'd recommend with The Sovereign??? I hope you can help.

I disagree that best filter is of stainless steel construction. It is true that some plastic filters may leach out contaminants under right conditions (acidic water) but those are usually low quality filters (mostly imports) not being able to pass leach test. All of Doulton filters comply to be in contact with potable water source.
IS100UC and IP100UC contain the same Doulton Ultracarb ceramic filtration element.

Compare with the Sovereign? Yes! Regent I found on the following link: http://www.doultonusa.com/doulton_water_filters/Imperial-high-flowrate-RegentI.htm
Both use Doulton Imperial Ultracarb ceramic cartridge.