Do they sell all terrain tires for 2008 suzuki grand vitara and how can I get more horse power for my vehicle?

I wanted to know if they had all terrain tires for my 2008 4x4 suzuki grand vitara. If so, Is it worth getting them, do they make a difference on off roading or highway? Plus how can I get more horse power? do I change my filter, what about thicker spark plug wires, does that work? Is there better spark plugs for horsepower? have u heard of "SuperCharger Turbo Fan Turbonator Tornado Fuel saver" if so do they really work? what can I do? Thanks