The author of the YouTube video you have linked to is based within the United Kingdom, hence are you from the United Kingdom too or from the United States (or other)? If you're from the UK, you don't need to convert your budget into dollars, as we can assist in GBP since I am from the UK too.
Regardless I'm going to assume you're from the United States and your budget being $1,200 USD; if I'm incorrect, please correct me. Luckily you can purchase cheaper components from the United States, hence you'll end up with a better build with your budget. Again please correct me if you're not from the United States.
For your budget I'd go with Intel, a better power supply and we may be able to squeeze in a better GPU too. Without further ado, I'd recommend the following.
PCPartPicker part list /
Price breakdown by merchant
CPU: Intel Xeon E3-1231 V3 3.4GHz Quad-Core Processor ($247.98 @ SuperBiiz)
Motherboard: ASRock H97 PERFORMANCE ATX LGA1150 Motherboard ($89.99 @ Newegg)
Memory: Kingston Black Series 8GB (2 x 4GB) DDR3-1600 Memory ($75.99 @ Amazon)
Storage: Toshiba Product SeriesT01ACA 1TB 3.5" 7200RPM Internal Hard Drive ($49.99 @ NCIX US)
Video Card: Zotac GeForce GTX 770 4GB Video Card ($339.99 @ Newegg)
Case: Corsair 300R ATX Mid Tower Case ($59.99 @ Micro Center)
Power Supply: XFX 750W 80+ Bronze Certified Semi-Modular ATX Power Supply ($84.99 @ NCIX US)
Optical Drive: LG GH24NSB0 DVD/CD Writer ($13.50 @ Newegg)
Total: $962.42
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2014-08-21 18:26 EDT-0400
P.S. Why do you want the frequency of the CPU to be 4.4GHz at minimum? The frequency isn't an indicator of performance; a Pentium 4 at 7GHz is significantly inferior to an i7-4770 at 3.4GHz, the i7 would run mile laps around the P4 any day regardless of frequency. (I understand the P4 is ancient technology, I am simply referring to it to illustrate frequency is not of significant importance with today's technology.) If you were to purchase an i5 and overclock it to 4.5GHz, the processor I've selected above would still be arguably better.
The build above includes a Xeon E3-1231 v3 processor, which is equivalent to the i7-4770 yet more affordable; it's quad-core with Hyper Threading (4 cores / 8 threads). I've included the GTX 770 you desired, however you can always switch to an AMD card for similar or better performance, yet for a lower cost. The power supply I've included is a XFX unit, whereby the OEM is SeaSonic (arguably best in PSU business) which is also 750W and semi-modular (allowing you to use only the cables you require).
The above build is better than the build within the YouTube video, whilst within your budget at a total of $962.42.
All the best.