Seems fairly over kill to me.. But assuming ur hardware is viable, as in The pcie slots will allow the graphics cards yo fit and run in full lanes etc. ..your issue seems to be that ur motherboard and case is not lining up...
Then the only option is to customise the case you want, or make ur own using part of thr case that u like, it wont be easy but its doable...and im assuming cash aint an option since ur splashing out this amount of dollar...
Or is this theoretical?
If it wont fit the case ...IT WONT FIT THE CASE...... Simples (meerkat voice stylee)