You can pick up a decent diamond water stone at a kitchen knife store,
http://www.dmtsharp.com/products/whetstone.htm They are compact and only require a little water to lubricate. Properly done, you will get a excellent edge. This is what I use to keep my Japanese sushi knives razor sharp. A steel is to be used to hone the knife, which maintains the sharp edge.
20 degrees is the normal angle you want to hold the knife to the stone in any case.