I personally use two that do and have been please with both of them. I'll briefly describe each below:
WASD CODE Mechanical Keyboard
WASD makes many keyboards and can customize them to your specifications (layout, key color, mechanical switch type, mac/linux/windows, etc.). The CODE keyboard is especially nice and has a clean layout, white backlighting and neutral font (Helvetica). It's made with two types of switches (Cherry MX Clear and Cherry MX Green with rubber o-ring dampeners). I personally use the CODE 87-Key - Cherry MX Green (they also make a 104-Key version, if that's your style.) While the Greens require more force than most other keyboards, I've found it inconsequential, partially because of the dampeners.
Since you mentioned having a Mac specific layout, the CODE keyboard has a DIP switch on the back of the keyboard that allows you to set the keys at the hard wear layout. Also note that the command (⌘) key is blank but can be replaced with a Mac specific version, if you so desire, and can easily be moved to the usual Mac layout—a key puller is included with the keyboard.
There are many other advantages to this keyboard, including n-key rollover, so definitely have a look at their website.
Razer Blackwidow Ultimate
I also have the 2013 Razer Blackwidow Ultimate (2014 version), which as far as I can tell is only sold on Razer's website. It uses Cherry MX Blue keyboard (great for typists) and has a very solid build to it—e.g., key backlighting, braided cables, usb, microphone, and audio ports, and a solid frame. However, while the hardware has so far been solid and I haven't had any problems with the keyboard itself, the included software (Razer Synapse v2.0, which manages macros and macro profiles) has proven quite buggy and as far as I'm concerned, worthless. Thankfully, you can forgo the software and simply use the keyboard as is.
I tried the mac version but was immediately put off by the glossy surface. Too each their own...
Matias Quiet Pro
I also tried out the Matias Quiet Pro. It has a great feel to it and is relatively quiet, if that's something you're interested in. While it is built well, I didn't like the plastic that formed the base: it looks cheap to me. Additionally, the frame wasn't quite as solid as the WASD and Razer keyboards previously mentioned.
If I had to buy again, I would not hesitate to buy one of WASD's keyboards. They're absolutely solid.
There's a great site that has a large collection of mechanical keyboards you may peruse. Have a look at MechanicalKeyboards.com.