Wheelie bar on Glamisdunes.com is the 1 to ask... I think you will have to go with external balast but I am no expert... That Light thread is mine and I cant say enough about them.. They are great!!! Cheap .. Reliable... I have beat the Hell out of those things and they have proven themselves to me. I have 1 with the glass broken out and it works great still You can splice into the existing wires but I would check the gauge of wire that is used if you run them on 1 or 2 wires. If they run all separate then You are good. To me I would go with the cheap ones and call it a day. They have 4" out now so they might work better for space saving
Capt