The Ace Hardware 46764 water filter housing can use any water filter that is approximately 10" long x 2.5" wide. All of our 10" x 2.5" water filters are located here:
http://www.waterfilters.net/culligan...ch-Filters.htm
Some of the more popular replacement filters for the Ace 46764 filter system are located here:
http://www.waterfilters.net/culligan...filters/P5.htm http://www.waterfilters.net/culligan...ilters/S1A.htm http://www.waterfilters.net/Pentek/w...lters/CW-F.htm
You should also replace the o-ring every couple of filter changes. The o-ring seals the water filter housing cap to the water filter housing sump to prevent leaks. It is important that these are in good condition. The OR-34 o-ring can be purchased here:
http://www.waterfilters.net/Culligan...g_p_0-191.html
A filter housing wrench is recommended for easy removal of the housing sump for installation of the new water filter:
http://www.waterfilters.net/Culligan...h_p_0-279.html
The following UB-1 mounting bracket comes with screws and can be used to mount the water filter housing:
http://www.waterfilters.net/Culligan...t_p_0-290.html
If you need to replace the Ace 46764 housing, you can purchase the replacement water filter system here:
http://www.waterfilters.net/culligan...ings/HF360.htm
You can also purchase replacement sumps (bottom part of housing) and replacement caps (top part of housing).
You asked if this system was the best system for under your sink. This is a good system to have hooked up to your main faucet for sediment reduction and chlorine taste and odor reduction if you choose to purchase a carbon filter. However, for drinking water, the best type of system is the Reverse Osmosis system. RO systems reduce dissolved solids such as nitrates, sodium, barium, etc. Our RO systems are located here:
http://www.waterfilters.net/Filters/...se-osmosis.htm