Here's a list of (chocolate) substitutions:
http://www.landolakes.com/mealideas/Substitutions.cfm
And a post with a cocoa caution:
http://www.recipelink.com/mf/0/53159
HTH
I must share a new recipe I was told about this morning by a friend of mine. The most simple fudge ever. 2 ingredients and 1 1/2 minutes is all it takes. Ready?
1 bag of chips
1 tub of frosting
micro for 1 minute
stir, micro for about 30 more seconds until it's creamy
pour into a 9x9 pan
They have been making every concoction (sp) they can think of: mint chips, fudge frosting, strawberry frost. raspberry chips, caramel chips, fudge frosting. etc. It's endless.
Just thought I'd share. I am going to try it tonight.
Karen 
kaka- i'd love to hear how that comes out please. 
Any kind of chocolate chips. Mint, peanut butter, butterscotch, white etc.
My friend said it was to die for. The mint chips with the fudge frosting was like the mint meltaway candies.
Yummo
You could. Here is a substitution chart I posted awhile back. The only thing is that you will have to add a lot of sugar and I don't know how much that would be.
There are some fabulous recipes for fudge that you use cocoa. Our old family recipe calls for cocoa rather than chocolate chips and it is the best fudge I have ever had (and trust me I have had a lot of fudge)
http://www.cakecentral.com/cake-decorating-ftopict-50415-substitution.html+chart
Quote by @%username% on %date%
%body%