For my first hanger, I would go with 2 x LEGO 30225c01, because it's easier and cheaper! in fact, how much would be explensive do a SNOT hanger of 50cm x 25 cm??
I also think that LEGO is made of things that fit togheter... so i like to have also dots in the floor to fit minifigures on them... minifigures can't just floating on the smooth floor... very unstable...and TIE fighter 7146 resting base, for example, should fit on some dots...
so I buy 2 x LEGO 30225c01 and see what happens... maybe I will do something good...