Lvjunior,
I believe your new set up is actually putting more load on the stock switch, wiring, and dimmer switch than a stock Sport Model does. Here is why. A stock Sport pickup only has one bulb per side turned on while in low beam. I assume yours has both bulbs on, on both sides. That is doubling the current. Secondly, a Sport, on high beam does have a relay from the factory to run all 4 bulbs at once.
I'm not telling you what to do by any means, just wanting you to be informed. I would think that your ON/OFF headlights switch, as well as your multifunction switch are at risk of burning out at an accelerated rate. I would guess that the harness from SUV or making your own from Daniel Stern is much cheaper than buying the multifunction switch an the ON/OFF switch..... Good luck!