I am very happy with my AsRock OC Forumula and the quality of components that AsRock used in this board.......they've improved a lot on quality + feature for the price. However, I'm using the previous version (Z77 with my i3770k) and I think the Z87 is about $100 more.
Along with ASUS & Gigabyte boards, checkout the AsRock boards as you should be able to get more bang for the buck........the Z87 Fatal1ty Killer got some good reviews and is going for around $129.
I would definitely go with the i7 even though it costs more, as it's a better proven product than the AMD. The i7 should also work really well with video/audio editing.
Pick out good (quiet) quality components, and the sum of all these should produce a good quiet DAW that should last you at least 5-7 years.....which is my goal.....:))
Here's a Fatal1ty review with a 4770k showing its peformance on video encoding and transcoding:
http://www.guru3d.com/articles_pages/asrock_z87_fatality_killer_review,13.html