As far as monitor goes, I would recommend something like this

http://www.ebay.com/itm/Perfect-Pixe...item4ac52ae4aa

Having said all of that, I would add one more thing. If you're willing to delay gratification, I would recommend spending more in the CPU/Motherboard department. I'm confident the 6300 listed above can handle wow and other games you throw at it. However, with a couple hundred more you could get into an Intel based solution that would be newer, better feature set in general. IE it's not going to feel old in a hot minute. In which case, I would recomend something like this...

PCPartPicker part list / Price breakdown by merchant

CPU: Intel Core i7-6700 3.4GHz Quad-Core Processor ($297.99 @ SuperBiiz)
CPU Cooler: Cooler Master Hyper 212 EVO 82.9 CFM Sleeve Bearing CPU Cooler ($19.99 @ Newegg)
Motherboard: MSI B150M MORTAR Micro ATX LGA1151 Motherboard ($83.88 @ OutletPC)
Memory: Crucial 8GB (1 x 8GB) DDR4-2133 Memory ($28.99 @ Amazon)
Memory: Crucial 8GB (1 x 8GB) DDR4-2133 Memory ($28.99 @ Amazon)
Storage: Kingston HyperX Fury 120GB 2.5" Solid State Drive ($42.99 @ Adorama)
Storage: Hitachi Deskstar 1TB 3.5" 7200RPM Internal Hard Drive ($44.00 @ Amazon)
Video Card: Sapphire Radeon RX 480 8GB Video Card ($249.00)
Case: NZXT Source 210 (Black) ATX Mid Tower Case ($36.99 @ SuperBiiz)
Power Supply: EVGA SuperNOVA G2 550W 80+ Gold Certified Fully-Modular ATX Power Supply ($70.98 @ Newegg)
Other: X-STAR DP2710 LED 2560x1440 Samsung PLS 27" Monitor "Glossy" ($189.90)
Total: $1093.70
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2016-07-06 12:27 EDT-0400

This one comes in just over 1,000 total including the monitor. Additionally, there's plenty of room to upgrade later, grab a second 480 for example or add more ram/storage if you so desire. You won't be overclocking on this, but for the price you should have a pretty good experience in normal 1440p gaming as well as 5 boxing. As with the first list I provided, you can get it a little cheaper if you don't need certain things (hard drives, case, etc). When on an extreme budget, recycling can come in handy for those and save you a hundred bucks or so.