I used a JK turn signal enclosure obtained from www.rockauto.com/
for mine. It has the CJ look which I wanted but even better, it accepts the stock TJ bulb enclosure without modification. A 3 1/8" hole saw and you're done. I did this mod while I was installing the MCE flattie fenders so I won't be any help so far as modifying the OE fenders go.
If you want to do this mod, let me know and I'll give you the inside scoop on how to lock them onto the grill without any additional hardware, silicone, etc. which allows their easy removal for bulb replacement.