you need to factor in rocker gear, exhaust and intake, all of which will be more expensive to prep, even if it’s truly no more to set up the W5 heads over an edddie type replacement head( which I find hard to believe)
after reading what your intentions are, the W5’s would probably be last on my list of choices….and I am a guy who raced those heads for years…it’s even still in my handle here, and elsewhere.
Listen to good advice!