In my experience, you can "safely" upgrade your headlights to higher wattage bulbs. My Jetta came with 55W/60W bulbs and I upgraded them to like 90W/100W. The difference in illumination was incredible and I did not have a problem with over-heating. In my G35C, I used to run Philips Rally H4 90W/100W (stock is 55W/60W) and I didn't have a problem with those either. I did notice a lighting improvement with them, but it was really only noticeable on roads/highways without street lights. Of course, the bulbs were also noticeably hotter and I felt the performance difference was not worth the risk.
So here's my advice:
You have two good options.
1.) Go to this site:
http://www.powerbulbs.co.uk/ and purchase a pair of Osram Silver Star bulbs. This site sells the Euro-spec version of high quality bulbs...being Euro spec is key. They are brighter and have a better beam pattern than the US version. Shipping is included with the price of the bulbs and it takes around a week to 10 days to get to you. Being brand-new Euro-spec high performance bulbs, you should get the best overall lighting performance.....the road illumination is as good as (if not better) than the higher-wattage aftermarket bulbs you can buy and you don't risk overheating and you will pass inspection!
2.) Purchase a D2R 4300K Xenon Kit. The kit includes two bulbs, two ballasts, and all the necessary wiring to setup your car with Xenon headlights. This option will give you by far the best lighting performance without overheating as Xenon bulbs only run at 35 watts, but it is costly (a couple hundred dollars plus installation if you can't do it yourself). You can purchase a brand new kit off of eBay.