You CANNOT use the Japan/Australian/UK spec H4/Fog lamp assembly in the US for a couple of reasons:
1) The beam pattern is incorrect. US and Euro lights will have the beam rising toward the right. The Japan spec lights which mimic the Euro pattern will be flat on the right and rise toward the left of the car. This will cause road signs to not be illuminated, and more importantantly, you will blind other drivers.
2) The wiring is incompatable. You will need to cut out the 9006/9005 connectors and create a harness that causes the low beams to switch off when the high beams come on (relays and a diode). Given that you sound like you want a lot of light, running 80/100 or 90/130 H4 bulbs will not work with both filimants illuminated (to much heat).
Finally, have you tried the HIR bulbs, they offer a significant upgrade. If you have and they are not cutting it, I would suggest the following. Take a look at these hella units that are Dot and ECE approved. They are used for many hi end retrofits and race cars. Their output is unreal and they can be purchased in HID fitmants if you want to go nuts. Best part, they are fully legal, crap all over H4 lamps. Worst part, you will have to fabricate the mounting brackets/assembly.
Check this link for parts:
http://www.rallylights.com/hella/90mm_modules.asp
Here is a link showing how they look at night from a car

as well as detailed instructions on how the guy retrofitted:
http://bellsouthpwp.net/m/u/mulgeary/Hella90/
These links for information about retrofiting:
http://faq.auto.light.tripod.com/
Finally there are a lot of guys retrofiting things like BMW projectors to their cars. I would go with the Hella's, they are cheaper and work as well. Here is a site with tons of retrofit information.
http://www.hidplanet.com/forums/
BTW, if you did the Hella retrofit, and can fab up the parts in a kit form, you could probably make some decent money selling the kits. They aren't that complicated to make, just take time. The parts cost for the lamps is a very reasonable $240 and there is no way the H4 lamps will even come close, that is assuming they were the correct fitmant which they are not (I have run Hella and Cibie H4 and 4 lamps systems for years, I know how they are).
Cary