You might find that the larger versions of the strokers are easier/cheaper to balance using the 50 oz versus the 28.
I realize you are talking 302/355, but on the 351s, 393Ws are easily balanced using the 28 and with reasonable weight pistons only require a bit of lightening of the counterweights. On the other hand 427Ws require 50 oz stuff plus a couple of chunks of heavy metal.
Look up Dave Williams' site and read how much trouble he had balancing the bigger stroked 302s. You might even e-mail Dave with this question. I defer to him.
http://angelfire.com/ar/dw42/index.htm