Too late now but if you take it apart again you can sand down the back of the grill to let more air in, I found that a very course bristle like disk worked the best, it was $4-5 at Harbor Freight.
Lights look cool, really, but are going to add the the overheating issues so a bigger radiator will help but more air absolutely will also as the fan cannot pull in enough air to compensate.
I have not ran driving lights since my last rally back in the 70s', Datsun 510 with four 7" Hella high/low headlights, two 8" Hella pencil beam driving lights and two 8" Hella fog lights aimed to the side a bit. I could see better at night than in the day, all the potholes and bumps, really stood out and made it easier to go fast, back then doing 100MPH on unknown gravel roads was pretty intense and fun