I would go with the cast heads and have them ported and worked and use a cam that can work the head 100%.The eddy heads are good,if you have a big cube motor and 600-700 lift of cam,if not,use dthe cast units,mrmopartech
it is just the opposite..the w2 have bigger ports and can be ported to out flow the eddies...and require larger cams and more rpms ...
question is how fast do you want to go and how much money do you have?
depending on what version of the w2 you have or can get the cost of the rocker arms can be around 1000 bucks.....plus offset shafts..and stands..
w2 econos can save money some money on shafts since they are drilled on center and no stands are required...
you need w2 headers and intake..
eddies can be easliy ported to flow over 290 cfm... existing rockers...intake, headers can be reused...
there are Indy alumnium heads, high dollar w-8 and w-9 heads....
there a cast heads from EQ based on the magnums...and now RHS/Indy has a new cast head that looks promising but no one has gotten their hands on them yet.
again...how fast do you want to go and how much do you want to spend?