To save money, they don't have to be the aluminum Magnum heads, the iron Magnum heads would do just fine (either the EngineQuest ones, or uncracked stock Magnum heads). You would probably run about .5-1 point less CR, but with today's swamp water gasoline, that isn't a big deal.
According to the video, there was already $6K in the 410 stroker. Using either a good used 360, or one that you own already have, with maybe just a basic good rebuild (~$2.5K), and new complete iron Magnum heads (valves, springs, retainers, locks and guides installed, ~$1K or so), you can come very close to beating the 410 in the video, perhaps even bettering its numbers with a well chosen cam and a good tune.