Raku is another name for a Reichenbach glass Iris Orange. It comes in frit and rods and is sold by many of the glass dealers like LBSupply which is where I usually buy mine from....Jon is great!
LE member, artflower, has some for sale at great prices in both frit and rods.
I just bought some from her to give to my neighbor as a Xmas present.
You could PM artflower and see if she still has some. I like to support LE members so I tend to purchase from them whenever I can. LBSupply is an LE member too.
Have fun!