Hello,
I just went through the same thing, I ordered the rear work light switch and pair of brackets from www.tractorsmart.com
I popped the roof off and plugged the switch in and then found out the work light wires had already been run out to the 4 way flasher lights so I hooked the nice kubota brackets up and put my own lights on. The kubota brackets replace the nut holding the 4 way flasher bracket on. I bought some bullet connectors to put on my lights so I didn't have to cut the kubotas wires.
Whole thing took 2 hours including taking the roof off which I could have skipped if I had dug around for the connector a bit more through the switch hole.
I looked into cheaping out on the switch and brackets but really it makes for a clean install.
Total Cost:
For the L5030 cab the rear work light switch is part number T1065-75370 price $27.26