So I converted to LED a while ago. I have 2-48 watts going forward which are hugely bright (I have a fairly good photo series of how the brightness changed from the bulb to 24 watt led to 48watt). I also hung 2 24 watts off the back of the canopy, and switched out the tubs light as well. I abandoned the lower light position in favor of just under-rops. There are some serious deals on light bars and I probably would use one instead of the individuals I have,although I have to say I like being able to grab one and point it toward the work, and keep the other pointing at the way I am going. Make sure you buy FLOODS, not spots. Good light bars will be designed with floods at the ends and spots in the center.
I want to caution you on a few things. Your machine probably does not have a standard alternator, but more of a magneto. In the beginning of LED Bulbs, there were some serious issues of LED's failing due to the nature of the magneto power. I believe the issue has been resolved in the LED Circuitry design but I would check with other tractor owners. While tempting, I would not exceed the amperage of your current bulbs (If they are 35 watt, I would not get any higher than 35 watt LED' (A bar could be 70 watt). But this being said, you will fall off your seat when you find out how amazingly bright a 35 watt led is compared to a 35 watt conventional bulb. And in my reference to wattage, I am talking true wattage, not "This bulb compares to a X watt bulb".
Finally, I got my lights off of Ebay and they came from China. I do try to buy american but from my research LED's are not manufactured in the US. On top of it, 90% of the housing you see for sale are chinese manufactured. These "made in the usa" from what I see are just assembled. So I have had no problems with my chinese bought lights. YMMV.