Having just had to replace an ASUS component - the graphics card, I'm a bit wary of ASUS. I replaced it with a Geforce GTX 660 which is miles better - so I would definitely endorse the Nvidia choice, especially if you also plan to run a DAW - its system footprint is negligible (unlike the ASUS, which was huge).
My PC, sans monitors but including the Windows 7 system builder OS, came to just under £750. It's as follows:
Gigabyte MB 970A-DS3, 3xUSB 3 and 6 USB 2, SATA 3 and Dual BIOS
AMD FX8350 8 core 4ghz processor
Some kind of whizzy CPU cooler I can't remember the make of - not liquid cooled, but lots of copper pipes and fins . . .
Geforce GTX 660 with 2GB onboard
PS is Corsair 750
Couple of DVD writers
Case has 3 super quiet fans
TP-Link dual aerial 300mbps wifi card
No SSD, I started with a 2tb Western Digital drive and added another 3tb later (less than £80 if memory serves). I don't need a fast boot time, 40 seconds is plenty quick enough me - the kettle can't even boil in that time. Everything comes out on the experience index as 8, except the spinning disks which come out at 6 - like I care
One thing I forgot to mention - the physical dimensions of the Geforce card. It is BIG, or rather LONG. So you will need a full size tower case to fit it in.