If you can stretch your budget a bit, get the ASUS VS247H-P http://www.amazon.com/gp/product/B005BZNDS0. It's a 23.6" monitor with a 2ms response time. After rebate it's about $139.
Well, the CM Storm Stryker White http://www.amazon.com/gp/product/B008O2HOI2 would have been my first recommendation but I was trying to stay with a mid-tower for you.
The Storm Stryker is a full tower but a really excellent case.
The NZXT Phantom 410 http://www.amazon.com/gp/product/B006I2H04I is an excellent mid tower case. It has plenty of cable management and airflow as well.
In that case the best card to go with is the EVGA GTX Titan Black http://www.amazon.com/gp/product/B00IKQOPZW would be the best GPU for what you want.
It pretty pricey but will be the best performing GPU for you.
I'd also recommend checking out the ARCTIC Accelero Hybrid II http://www.amazon.com/gp/product/B00I3ETT84 which is an all-in-one GPU water cooling kit.
What is your budget? You would need a more powerful power supply most likely.
Something like the XFX PRO650W Core Edition http://www.amazon.com/gp/product/B0045L5LGI with an ASUS GTX 780 DCUII http://www.amazon.com/gp/product/B00DWV3NM6 would be an excellent setup for OpenGL rendering.
Just go ahead and get a MSI R9 270X Gaming http://www.amazon.com/gp/product/B00FR6XP6I and wait for Maxwell.
The 270X should be able to nearly max every game out right now at 1080p.
The ASUS VS239H http://www.amazon.co.uk/gp/product/B00D6L4Y9I would be an excellent choice near your price range.
It's an IPS panel with a small bezel and accurate color reproduction.