FWIW, you don't give us much to work with. What do you have, what are your desires? What is your stock engine? Building up the stock 4.0 is probably the easiest and cheapest way to make power. Depends on how much work you want to do and how much power you want, and what you are starting from.
A GM based swap is probably the easiest way to make bigger power,but it does take some knowhow and effort. There a several good build threads here on the board, thecodemonks Rocky, limeyjeeper, 70barracuda's Driving on the street to Street Truck pop to the front of my brain. Look in the Epic Builds section. Probably a dozen of them, if you look a little.