If you are doing a full rebuild and have to buy pistons, rods, grind crank and bore the block. A stroker is the way to go. If you shop around. 4.250" cranks are available for not much more than a stock crank kit. 6.385 rods are out there for not much more than a set of bolts and re-size of the stock rods. Pistons are about the same price as hyper replacements.
The only really added expense is a balance job, which should be done on a rebuild anyhow.
Heads= Best bang for the buck is the Pro-Comp and clones. Best price is Ebay. Price is better than I can get from my wholesalers.
You will hear a lot of flack about these heads. Mostly from know it alls that diss anything they think is made in China (these heads aren't, they are manufactured by the Aussies). Then shipped to China, then shipped here because of trade rules $$$$$.
I have been selling/using them for years. Only complaint was about some external casting flash. I showed the customer some new GM (Edelbrock) castings and they were worse..
Back on track:: Buy just the castings and fill them with Manley valves and Comp Engineering parts.. You and your pocket book will love it..