It may be a dumb question. But ......
Has anyone tried to cast there own acrylic panel ?
Maybe embed the IR emitters directly into the panel
during the casting process ? 
Maybe some kind of product like this :
http://www.delviesplastics.com/mm5/merchant.mvc?Screen=CTGY&Store_Code=DPI&Category_Code=Casting_Resin

or maybe something like this
http://www.hkresearch.com/bulletins/R0265%20ACRYLIC%20MODIFIED%20NPG%20ISO%20CASTING%20RESIN.pdf

I seem to remember doing a project with some stuff like this when i was much younger....

someone did that long time back on the forums… if you look deep u’ll find the pics as well… however the results for such solution do not differ drastically from the standard ones .. so overall its not worth the pain, money n time .... and in case one of the IR led blows up .. i wonder how i’ll fix it !!!

its a good idea tho but casting the clear silicone layer is enough pain for me to really venture out into casting my own acrylic!!!!

cheers!!!