CF and SD Cards for 5dm3

I know this topic has been beat to death but I'm still kind of hazy about the write and read capabilities of the 5dm3, and about CF and SD cards in general. In the past, I've usually just bought the fastest good sized card available. For my t2i, I have a Sandisk Extreme 32gb card (http://www.amazon.com …DL34Y/ref=wms_o​hs_product).

With my impending purchase of the 5dm3, I wanted to make sure I got the best CF and SD cards.

I know the camera supports UDMA7, which I believe only Lexar manufactures right now. However, the prices are crazy. What's the difference between the Lexar 128gb 400x and 1000x? Does that refer to speed (http://www.amazon.com …3Alexar+128gb+u​dma7&ajr=0)

I'm mainly a Sandisk guy but if the Lexar CF cards a good deal, then I would consider it.

I guess the main point of this post is to see if someone can provide a general guideline of:

1) The cards that would just get by on the 5dm3
2) The cards that would make the most sense speed-wise and price-wise (and why)
3) The absolute best CF and SD cards out there right now that would work in the camera

Thanks!