The easiest and cheapest solution is to either use hop bags/socks or build a hop bag hanger which is also known as a hop spider and other names. Google for those and you'll find some simple, easy designs you can build with a quick trip to the hardware store.
If you have a Blichman kettle, you can try the Hop Blocker. Keep in mind that this is only designed for use with pellet hops (which you use anyways).
A bazooka screen is an option but not as easy to install and use as the others.
A false bottom in the kettle is a great option but only works with whole/leaf hops.
A hop back is an outstanding option but a bit more advanced as far as building one yourself and incorporating it into your system. The Blichmann Hop Rocket is a great product and works very well but runs about $140. A wort pump helps but isn't absolutely necessary depending on how well you can utilize gravity in your setup. Hop backs are designed for whole hop use and act as a very effective filter for trub, not to mention the amazing hop character achievable with one that you just can't get with simple whirlpool additions.
You can still use hops for a 0 minute/whirlpool addition with any of these methods.