Why would anyone who is sane want to filter water that will be used to flush toilets and used to water lawns or wash their cars?
This could be really expensive as what else besides chlorine and which heavy metals and why type of sediments do you also want to remove?
The most cost effective filters are point of use NOT whole house unless your using swamp water. Filters are great as long as you had the water tested to know what you want removed.
Point of use for a shower head are great and can cost as little as $15 and then a filter under the kitchen sink for the instant how and ice maker to the refrigerator. Filtration is the new scare tactics to pray on peoples phobia.
Whole house is normally a total rip off in my professional opinion. Always ask to see the master plumbers license of the installer and not some sales representative from a filter company that works on a commission. Many big box stores as well as E Bay and Amazon.com have an amazing selection of CHEAP but great filters