hmm "I do not know what is wrong with you mon, but whatever it is, it is not a small thing" - Cool Runnings
Option 1.
pabbi says the m³ at 30v doesn't drive the k1000s with enough punch. Voltage swing is the issue I'd think. I've been looking into this issue and have come up with a few solutions to it - the key one is the borbely mosfet regulator that can supply up to 40v per rail, abeit more expensive than a steps.
http://www.borbelyaudio.com/eb202254.asp , a diyer would still need to make a (nice) rectifier to feed it, but I think that if you were to set the power supply to 38V(as there's a 2.8v drop across the circuit), plugged in some opa637s/627s, you'd have an amp that could swing from the rafters, voltage wise. Couple this with 2 inch mosfet heatsinks, with high mosfet bias current, say 120mA, and you'd have a really nice solid state class A amp for them.
Option 2.
Borbely has a mosfet amp (completely solid state) and a hybrid amp(tube/mosfet), both designed for headphones:
http://www.borbelyaudio.com/eb602210.asp
http://www.borbelyaudio.com/eb804421.asp
Both can handle 24+- supplies V and should be more than capable of powering a pair of K1000s with authority. One of these combined with the aformentioned regulator, combined with appropriate rectifier/transformer would certainly drive the K1000 with authority.
I think this would fit in your budget.
Just opening up the page for ideas
oh and iagaudio.com has some nice cases you could stuff those in..