Hey Rob,
Glad you found us.
Lighting is not unatainable, however it is not cheap, and involves a bit of research, ( I know, that's why you asked..) and wiring. There are several guys who have plated their KX for the street.
Baja Designs :https://www.bajadesigns.com/NET/C-MCYCLE/MOTORCYCLE+PRODUCTS
Rocky Mountain :http://www.rockymountainatvmc.com/productDetail.do?navType=type&webTypeId=193&navTitle=Electrical&webCatId=20&keyword=OFF+ROAD+LIGHT+KIT&prodFamilyId=26724
There's a few places to start, a quick Bing resulted in 5 pages.
You generally get what you pay for,(20 dollar carbon reeds) are the reeds chipped, cracked or not lying flat against the reed block?
I think you would be way better spending the $20.00 on a service manual, There is lot's to learn about keeping the bike running and how to get the most out of it.
KX's have come with both carbs,
Tuck\o/