Hello,here's my 1.2kW SMPS built from junk parts.It's really simple and good.
SMPS is in fullbridge,uses 4 same switching transistors,you can use 13007,13009,2sc2526,BUxxx,BUTxx,BUVxx,and more....
This is self osc. SMPS
For power transformer you can use two EE33 in series,one ETD49,or other core...