Alas, none of the digital Coptic fonts I have looked at have been of very good design quality. I presume you’ve seen the various free ones available at e.g. http://www.travelphrases.info/gallery/Fonts_Coptic.html

Coptic is on the list of scripts to be supported by the SBL Font Foundation, which means I hope have the pleasure of designing two Coptic fonts (one Sahidic, one Bohairic) in the next couple of years, but I presume your need is more immediate.

I’m not qualified to determine which Coptic fonts are well-drawn, but MacCampus are specialists in non-latin scripts. Here’s their Pachomius Coptic.