Any fresh JDM engine from Japan now is going to be a lot more expensive because of the Yen situation. Only 18 months ago we were selling brand new FD2 engines for around £5k.
I would give Tegiwa a call and see what they have.
What is the ultimate plan with the car? NA or F/I? UKDM EP3 engine would be better for F/I due to lower compression. JDM LSD's are only around £550 brand new so its not so wallet damaging to go UKDM engine/transmission and fit the JDM LSD. While you are there, get a shorter gearset and final drive installed which will suit EG/EK
The K20 is still in high demand, popular with Exige/Elise conversions and now getting respect in kit cars too. Great engines.