I purchased an AcuFeed stitch in the ditch foot for my Elna for $29.99, and it's actually listed as being for the Janome. I was told it fits both brands. Works great! I got it from allbrands.com. I see their website now lists it as fitting Elna as well. I also purchased from them AcuFeed feet for quarter inch (which comes with a marked needle plate), and the Open Toe Satin Stitch. They also have an AcuFeed ruffler (which I did not get).
Here's a link to the foot itself:
http://www.allbrands.com/products/abp10252.html