I have two pairs of AKGs currently and some monitors.
I first bought an AKG K712 (which is their current flagship model) because they're open and have really good sound stage and transparency. They're not the flattest headphones ever but they do expose quite a bit of detail. I did a short mix test on them and they do translate quite well on speakers. The advantage of headphones is that you can really hear subtle EQ changes and details that you often can't hear on speakers (especially when it comes to reverb). These have a surprising amount of bass (perhaps a bit warm above 100 Hz but well extended below that; probably usable all the way down to 40-50 Hz but audible in the low 30s as well).
I also have the K550 (which is the same as the K553) which is a closed back pair but it sounds really close to an actual pair of speakers. Very even sound signature with great extended bass (quite a bit better than the K712) and excellent detail all throughout. Perhaps a bit lacking in terms of sound stage but still accurate and wide enough to be able to mix decently. They are excellent value for the money in my opinion. One of the best headphones under $200 (sometimes under $150).
My monitors are a pair of FX8s from Fluid Audio. They are 8" coaxial speakers meaning that the tweeter is in the center of the woofer which gives you a more accurate soundstage. They really do a great job of that. The sound fills the space in front your face quite well and there's a very clear center image for vocals for instance (but performance may vary due to room acoustics). Overall they sound quite balanced and transparent. Great deal for $450. Just make sure to get balanced cables and a decent audio interface (I have a Roland Rubix22). I had a USB ground loop issue (it's common with some monitors and interfaces) that bugged me but I seemed to have managed to get rid of it by connecting my PC to a different power strip and enabling the ground lift switch on the interface. Amplifier hum is pretty minimal with these speakers.