No the 780 series motherboards don't give you the proper control in BIOS for overclocking. They also lack the proper cooling capabilities to support any voltage bump even if it was supported. The 970 series is better, but still not great for REAL overclocking. You need a 990FX series if you want to get the most from your cpu.
To answer you're question, yes the ASUS M5A97 R2.0 is worth the extra money. The motherboard is the LAST part you want to skimp on.