The one I linked to is on a Noctigon so heat issues should not be that big a deal and foil would not be needed, especially with Nichia-level drive currents.
Cheapest option? Buy this host and nanjg driver. Then Nichia 219B from IOS. Should be well below $14. You will have a small EDC light with high CRI emitter. 
This here , from intl-outdoor. 26 $
configure it with a nichia and 4 mode (moon, low, med, high)
Can also go for fancy color golden host or sleek grey……
(i run my nichia’s from a nanjg 4x7135, pretty conservative as i see that intl outdoor runs it from a qlite 6x7135)
Rayus C01. Although it’s only a one-mode. Nice, nice color.
http://www.shiningbeam.com/servlet/the-275/****NEW****-RayUS-C01-LED/Detail
I got <$6.50 in my new Nichia 119 EDC.
What is so special about these emitters?
unmatched color rendering
like Killer said, the color is unmatched by any other out ther. also i have found the NW color of the 219b to be closer to daylight when using the light.
Thanks alot to all who helped, i guess the L3 would be the best choice? 
Also cri is really that much better in rl like on videos? i saw one nichiha smoked MT G2, like totally it was amazing to me…
I don’t have any flashlight with Nichia emitter. Maybe I can swap the Cree emitter of my 502b. Which one should I get, the one from IO (suggested by Chloe) or Kaidomain (suggested by se7en)?
Do you live in the US? If not the postage cost will kill the deal.
I know, i arranged with my friend to split the shipping cost, we will order 2x
To my eyes, there is a difference but it is not that apparent until you have a second light to compare with. Then it takes some consideration as it isn’t instantly apparent especially if you shine it on not so colourful things.
+1 From where?
For the 502b, just get the IOS drop-in from: http://intl-outdoor.com/p60-dropin-module-cuxp2-xpg2-219bt-p-798.html
The kd one is just an emitter mounted to mcpcb. Not really worth the trouble for a p60 platform, imho. Much of the appeal comes from easily changing between modules. If you insist on doing the swap yourself, get the led from IOS, as those have been confirmed to be the high-cri variant.
18sixfifty is a member on this forum that loves to modify and sell lights.
Thanks to all for the suggestions. I will get the emitter from IO and do the replacement. Will report back the result.
Hi guys, L10c fit 14500 cells? i got” Nitecore cell
Would it be brighter and by how much? 
Edit, is there any chinese clones of L3, with nichia led?