Somebody has already done it for you. JC Whitney has had these for a long time. At $27 and up though, you can do 4 cars. All it takes is a standard automotive relay, a relay socket (optional-standard crimp-on electrical connectors can also be used), a fuse and some wire.

another tihng i noticed is that when i pull back the switch, the highs are nice and bright, but when i let go of it they get dimmer

Answer:
That'* why you would want to this modification. To keep all of the light on as if you are holding the switch back.

no i mean that the high beam bulbs themselves get dimmer whent he swithc is released

Both the low and high bulbs have a single fillament, at least they do in my car, so the bulbs can not produce 2 levels of brightless. What you are seeing is:

Lows on = only low beams on (2 bulbs total)
Pull back on switch and hold = both lows and highs on (4 bulbs total)
Relase/highs activated = only high beams on (2 bulbs total)

They seem to be dimmer cause the 2 low beams turn off.

Right, the highs are obviously angled higher then the lows, thats why you can see a ton of crap while there both on

no, i have gone over this with many people and confirmed it, there are 3 stages when i pull back the switch, first i pull back the highs come on birght, i pull further until it clicks, the lows turn off, i release the switch, the highs get dimmer

Alrighty then.

Good luck with your project.

Hmm, who told you about those stages? At least it always feel'* like the highs and lows are on at the same time

OK. I just checked out my car. It'* a '90 so yours may vary as I don't know what year you have. Here are my findings:

When switching from low beam to high beam, the lows do go out after the click. So when you are holding the switch back, only the high beam is on. This is what you are saying except for the highs did not dim after releasing the switch.

When switching from high beam to low beam, the highs stay on after the click. So when you are holding the switch back, all 4 bulbs are on. When the switch is released, the highs turn off and things get a heck of a lot dimmer cause you are going from 4 bulbs on to lows.

Twister, if you get a chance, can you check this out on your car?