both are great cars, depends how fast you want to go
R32 is pretty much pegged at stock hp (unless you turbo/supercharge it = 5k+), but a great sound. dont forget roadtax on certain years is pretty hefty now too!
white ones are uber rare and worth having for the 'cache' / resale value
E30, straight to 300 bhp and beyond with a remap right up to 360 or more (jonnyc/Hurdy) on the std K04
pretty common (except white) but holding value well
get a drive of both in std form , then drive a remapped edition 30.