You'll be very pleased with the improved transfer rate of a USB 3.0 caed reader rather than a cable connection. It makes a difference on the larger D600 and D800 files. I use a Lexar USB 3.0 card reader that accepts CF and SD cards.
A couple of things to be aware of with the L-bracket. The RRS L-Bracket cannot be used with the plastic LCD cover. Don't even try it - it will pinch and crack the cover. The Kirk L-Bracket might work but I don't know.
If you use a cable release, the cable may be pinched when you mount the L-bracket in a vertical orientation. You may need to position the camera off center to avoid pinching the cable. The RRS L-BRacket (don't have the Kirk model) has a slot to create more space for the cable when you mount the bracket.
While the Markins lever release is adjustable, you don't want to be adjusting it every time you changes lenses or bodies. Stick with compatible plates - generally from one or two manufacturers. There may be very slight differences in plate sizes across different manufacturers due to manufacturing specs or paint/coating selection.