I have tried the new version of your IC2 Classic 1.6.4 and it works ver well with GraviSuite and Advanced Solar Panels.
I'm glad that I can play with some add-ons. I'm really welcome this new "IC2". 
Although I found a graphical bug when I equip my character with IC2 Nano Suit and Quantum Suit.
http://i.imgur.com/4lFCtiX.png
I don't know, what causes it, but should fix this before the 1.8 Update.