How to correctly make chocolate bars?
The secret ingredient of all Chocolatiers: cocoa butter...

I use a different brand of chocolate (Callebaut) so I don't need to add any cocoa butter, but as I've never used your brand before, directing you to their product line.

Be careful, because too much cocoa butter will make the chocolate melt in your hands and in your mouth! ;-) 

I would start off with 10% of total weight of additional cocoa butter and increase if needed (start with small batches as 7Kg is a lot of chocolate!)