also interesting to read:
http://www.mouser.com/pdfDocs/Cree-Power_Article_4.pdf
SIC mosfets, small switching power, 100khz, small inductors, you might need a better CPU though (arm? st?). Will cloudstash some notes here if you don't mind.
per 5kw
C2M0080120D mosfet $15
C4d10120d diode $11
400uh Fe-Si-Al AWG12*1*55Ts OD:63 x HT:26 $12 (Kool Mµ?)
looks like 132nh/t^2 @ 100khz, so maybe a
0077616A7 core?