What clock should I get?

I have PT 12HD, Mac, Avid OMNI interface running a black magic decklink SDI http://ift.tt/1QcvbUQ

I do lots of sound design/foley editing, and want frame for frame audio/video sync.

I have noticed that with my current setup, stuff starts drifting on/off and sometimes over time. Its still tons better than using the macs internal graphics card, but not perfect.

What sync box should i get?

The simplest solution is preferred.

I work mostly with 720 material, and sometimes 1080. Most of the time 25fps.


And then some questions:

How does this work again? I have an external clock. Sends clock out to SYNC HD (wordclock?), that in turn sends sync out to the avid omni interface via wordclodk?
The SYNC HD is master for the AVID omni interface. The clock also sends SDI sync (Black burst or whatever it is called?) to the black magic card?

I need to buy a SYNC HD and a clock to add to what i already have. Is there *one* solution that can do the same thing at a time, that would be cheaper/more stable etc? Or should I buy 2 seperate boxes?

Depending on the video format, do i need to manually set the up the converter or can it automatically detect what framerate/1080 etc?

Thanks!

I would like to get the most simple solution.

I have noticed, that i have to set the video sync offset to different values depending on what type of QT format the movie is encoded with. I would love to be able to only have ONE offset, no matter what i do. I always convert my videos to ProResProxy, but i still have to set the video offset differently.

Thanks:)

What clock should I get?