P67 or Z68 Motherboard for Music / Video editing?

I've looked around this forum but couldn't find the answer for my situation. As of now I'm looking at purchasing an ASUS P8Z68 PRO / DELUXE or an ASUS P8P67 PRO / DELUXE for a computer primarily used for my audio workstation and video editing (bit of a noob in the latter). Now, I'm mainly looking to have smooth audio work with very low latency and smooth video editing work (working with AVCHD files). I was told on another forum (GearSlutz.com) to go with the ASUS Z68 DELUXE over the others (though not thoroughly explained why) and to go with the EVGA GTX 560 gpu (will be using Sony Vegas 11, which recommends nVidia cards). However, if I could save a little money, I would like to change it up a little only if the performance won't be drastically different. Basically I'd like to know if theres any real advantage the Z68 mobos have over the P67s in terms of audio / video work (one faster? slower? more reliable?) Hopefully this will be the last wall I run into in choosing a motherboard! Also if anyone has any suggestions on a different GPU that would be extremely helpful too, such as going with the EVGA 460 1gb instead. Thanks and I greatly appreciate any help!

If you use Cyberlink Media Espresso which can use the Intel quick sync feature for video transcoding then Z68 but if you have no interest in using the media espresso program then get the p67.

Here's what intel has to say about Quick sync:
http://www.intel.com/content/www/u [...] neral.html

I transcode MKV files (720p movies) to avi files with media espresso and it takes about 15minutes opposed to about 35 minutes with handbrake.

Also the Z68 motherboard has the ability to use a small ssd with a large mechanical hard drive to speed it up a little bit. I dont find this feature very useful because it doesnt speed up the hard drive much. You'd be better off with a slightly bigger ssd and just put your OS on there.

You can also use the intel HD integrated graphics on your I5 but you'll be getting discrete card.

These are really the only difference between the Z68 and P67. If the price is within $10-15 dollars I would get the Z68 just because.

I have an Asrock z68 Extreme4 with an I7 2600k. I really like it