matching parts...

sounds ok, exception being the heads. The roush 200's will be a bit much, the roush 180's should be plenty for a 289.

I would assume you're going with the roush's because of the price, and I can't blame you. The intake ports flow quite well, but the exhaust ports need a little work to get them up to the same performance level. You may want to check e-bay(or classified ads) for some used trick flows, or edelbrock performer/performer rpm heads. The AFR's 165 are excellent as well, but they are pricey. Once you reach intake runner volumes over 180cc for a 289, your peak power rpm goes way up. Ideally, you'd want a head with maximum flow, with a smaller volume to keep velocity up.

Should be a strong runner once you get some heads put on it.

what gearing and transmission do you have?

how long is it going to be until you can get the new heads?

if its a long time and or your gearing is high that cam will be too big for a good street engine.
which brings another question, whats the intended use for this motor?

all i know is that intake sounds bad-ass