Dual Link adapter. if you use the cheap one, it will only top display at 1900 x 1200...
The cheap one is a single link adapter. While 1900x1200 is possible for DVI single link (anything with a pixel clock less than 165 MHz), the Apple 30" Cinema display has a single link resolution of only 1280 x 800.
The VGA display port adapter has a pixel clock max of 180 MHz. The hardware might be capable of 240 MHz with 6bpp instead of 8, but I don't think the drivers will allow it. Graphics card RAMDACs for their built-in VGA output can go up to 400 MHz (2048x1536 x 87Hz) but nobody uses CRTs anymore...
HDMI 1.3 can go up to 340 MHz (single link) which is only enough for 4K @ 38 Hz.
DVI dual link is 165 MHz x 2.
4K @ 60Hz requires a pixel clock of 534 MHz which can be done with a couple HDMI 1.3 or dual link DVI connections.
HDMI 2.0 will have a max pixel clock of 600 MHz.