I would try a good quality led globe KC. I have got them as reversing lights(globe replacements) in my car and working good. 

Can I ask the reason why you want to replace with LED's ?
My opinion of course, but they really don't do anything better( often worse) than standard filament bulbs in that application.
Probably the best units are the discrete LED boards like these from custom dynamics.
http://www.ebay.com.au/itm/Custom-Dynamics-Turn-Signal-LED-Inserts-02up-Amber-FR-or-RR-Pair/282570743726

As ya know am long winded barstead, sometimes.

Ok, so out of interest I've ordered a couple of the Osram LED bulbs I linked to previously.  Only risk is that they might be a little too long 52mm vs 48mm standard globe.  But I'm interested to try them out.  I'll update the thread when I get them.

I'll be interested to see how good they are.
I really have to question that they are 30w though.
The heat dissipation needs would be crazy, and need some serious heat sinking.
If you get a chance, can you measure the current draw ? That will give an indication of the true power.

I'll hook one up to a 12v charger and measure with a multi-meter that should be able to determine draw.

Am sure you'll have the second filament connection blocked like me KC. Take the tank off and give it a look. Love my CD front indicators :) My rear ones are still bulb. 

Custom Dynamics are the best choice, check them out at Revzilla.

My rears are single contact socket as well with 1156 bulbs :) Only the front was dual contact 1157 with one of the contacts blanked out which I fixed. 

I received the LED globes today and they work fine.  Unfortunately they were not a simple drop in fit.  The length was fine, but due to ridge at the base of the globe, I couldn't push them in far enough to twist them in.  I had to round off the metal base of the globe part with a file.  It was an easy mod, but it's a real shame these don't just fit straight in.




I had to round off the base of the globe part so I could push them in enough to lock them in.  Easy enough but a shame they didn't just fit straight in.



LED globe installed.



They are a fair bit brighter than the incandescent globes and much cooler running.  After having them on for a couple of minutes the incandescent globes are hot, but the leads are barely warm.

Well done KC. They look good. Thank goodness they run cooler. Imagine the heat generated just taking a corner or changing lanes. Talk about global warming!!
As a Volvo owner, I am proud to contribute to keeping the planet cooler by not being required to use indicators at all...

Just a follow up, I ended up getting some 1157 dual filament LED globes for the front indicators.  These are a perfect fit for the Harley indicator housings, they dropped straight in.  They work well and run cooler than the incandescent bulbs.  I just got these off ebay.