Im, sorry but i have to disagree, (i may vey well be wrong here).
There is Kh in tap water, less in N.Z than else where, in the states you will need to test your Kh & Gh. Chocolate gouramis are very delicate little fish in my experiance, they appreciate slightly warmer water, softer (Kh), and more acidic. They are happier in larger groups of 5-6 or more and do best with lots of plant matter.
Kh is in tap water, Kh maintains and stabilises a constant Ph, peat is not a type of filtration, it is placed in the filter or gravel to soften the water (lower the Kh and help to acidify the water as a result).
So Zazz your understand of Kh and Ph sounds like a good starting point.
You should be very carefull adding peat use less then add more every ten days or so, it can drop the Ph very quickly.
Yoou may wish to invest in a Ro/DI unit, make up your water place it in a barrel, put peat in a filter bag, use a pump or airstone to mix the water.
This will give you very soft acidic water to use for water changes etc.
Make sure you have no stones or grave in the tank that will add carbonates (Kh) to the aquarium or you will be in an up hill battle with Kh and Ph. You can test the gravel by soaking it in a bucket of water (testing before and after making sure you airate the water during test. You can test rocks by pouring an acidic solution over them if they bubble dont use them.
HTH
Ben