I can suggest a variety of things, but we’ll just focus on what you want to do, produce EDM & Beats.
For starters I’d say, stick to 49 keys. 25 keys tends to feel a bit limiting, and 61 is overkill unless you’re a very skilled player.
The others before me have already outlined the bigger names: M-Audio, Novation and Akai. Pretty hard to go wrong with any of them. They are also mostly in the same price category usually. Very economical and worth the investment, especially when getting started. Though I’m sure it’s a decent keyboard, I’d opt out of the Keyrig honestly. Considering your budget you could afford an equally good keyboard with a lot more features that will come in handy.
For producing beats, having any kind of pads will be a godsend. You’ll still have to set up your samples and drum kits inside your DAW, but being able to mash out beats physically is really a lot more intuitive. They also double up as automation switches (if you choose to do that). You’ll most likely use the keys for writing in bass lines and leads. Having the 49 keys here is handy 'cause you can split up the keyboard so the bottom is bass and top is lead, or however else you want to do it. Other than that, faders are handy for making adjustments and throws.
For producing EDM, I’d have to say knobs are what you want. Though a lot of volume automation is easy to draw, making filter/LFO adjustments to Synths is really a lot easier if you can just grab a knob. Also, if you have a favorite synth, you can just map your knobs to the controls so making sounds is more intuitive. You’re most likely to just program the drums, so pads are less important here. A good pitch bend and modulation wheel will come into play though, will save you some annoying automation work. You can usually map the modulation wheel to whatever you want, so get funky. You could map it as a global low-pass filter, or the LFO rate control. Let’s you get more expressive.
So in short, you’ll need a bit of everything, since you’ll be doing a bit of everything. Anyway, that was a long explanation, here are my recommendations.
- M-Audio Air 49: M-Audio just came out with these, has everything you want, pads, knobs, faders, wheels. Also has a small display, which might make things a bit easier to control. Fits in your budget. http://www.sweetwater.com/store/detail/AxiomAIR49/
- Novation Impulse 49: Very similar to the Air 49, aside from having a few less pads. Similar price. http://www.sweetwater.com/store/detail/Impulse49/
- Akai MPK 49: It’s sort of like an MPC/Keyboard hybrid. Seems a bit more focused on the use of pads here, faders and knobs laid out more like a small mixer. If the pads are anything like the MPC, then they are good. http://www.sweetwater.com/store/detail/MPK49/
- Akai Max49: I’m just adding this as Tarekith mentioned the Max25. Has touch faders, which I imagine removes the problem of non-motorized faders (though unless they respond well, I’m not one for digital faders). Once again, got the MPC pads but no knobs! Also costs a bunch more than the others. http://www.sweetwater.com/store/detail/MAX49/
For doing everything you’re looking at I’d recommend the Air 49. I’m only basing this on some experience I’ve had with M-Audio keys. They are good, not amazing, but do everything you want well. The layout seems more suited for your needs as well. If you were mostly interested in producing beats I’d recommend the Akai MPK 49. As an all-around tool the Air 49 fits the bill, doesn’t break your budget, and since it just came out should have decent support in the future.
My only other advice would be, if you can, try before you buy. I can imagine most large music stores like Guitar Center having some on display. Get a feel for them, and then decide. Once you do buy one, take some time to do some heavy MIDI mapping. Get everything set up so it makes sense, and try to make use of all the controls available. Hope this helps, good luck on your search!