The big difference between our boards (apart from the Intel-AMD thing) is that the ASRock will allow you to overclock while the MSI board will not. Neither will the 4690 CPU, regardless of motherboard.
Also, since it's an 8-series mobo you may need to do a BIOS update before you can use the 4690 with it, which can be difficult if you don't have a supported CPU laying around.
When it comes to longevity you'd be better off with the ASRock quality-wise I think, but that's hard to predict. The MSI has a CPU socket that'll probably be around longer though, allowing for easier CPU upgrades.
The 4690 will perform better out of the box for gaming. For editing/rendering etc the 8320 is better. The 8320 may also start performing better in the future as games start to utilize more cores.
You can use either board for upgrading the graphics card, no worries there.
This might be a good middleground, combining the best of both worlds with even better gaming performance at a slightly higher price:
PCPartPicker part list /
Price breakdown by merchant
CPU: Intel Core i5-4690K 3.5GHz Quad-Core Processor ($219.99 @ NCIX US)
CPU Cooler: Cooler Master Hyper 212 EVO 82.9 CFM Sleeve Bearing CPU Cooler ($29.98 @ OutletPC)
Motherboard: ASRock Z97 Anniversary ATX LGA1150 Motherboard ($84.99 @ Micro Center)
Memory: G.Skill Ripjaws X Series 8GB (2 x 4GB) DDR3-1866 Memory ($79.98 @ OutletPC)
Storage: Seagate Barracuda 2TB 3.5" 7200RPM Internal Hard Drive ($79.99 @ NCIX US)
Video Card: Asus GeForce GTX 760 2GB DirectCU II Video Card ($234.99 @ Micro Center)
Case: NZXT Source 210 Window ATX Mid Tower Case ($29.99 @ Newegg)
Power Supply: Corsair Builder 500W 80+ Bronze Certified ATX Power Supply ($29.99 @ Newegg)
Optical Drive: Asus DRW-24B1ST/BLK/B/AS DVD/CD Writer ($16.98 @ OutletPC)
Total: $806.88
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2014-09-07 14:53 EDT-0400
This build will allow for overclocking, a CPU upgrade to Broadwell when it comes out and great gaming performance.