Just mentioned on classics-l, http://www.gospelthomas.com/.
Some of the sayings exist in a POxy in Greek (saying 4 for example), but all have the Coptic, with access to a very helpful analytic interlinear.
There’s also a interlinear version of the whole book in pdf format. 
http://www.geocities.com/Athens/9068/x_transl.htm
Some day I’d be purchasing the Nag Hammadi Library, but until then I’ll have to go through Coptic. 