The binary distribution should come with all the necessary jar files. The projects you listed are required, but I wouldn't recommend a separate download/install due to the fact that struts is being compiled against specific levels of each of those libraries. If you mix and match, you might very well have... unexpected... results.
"Write beautiful code; then profile that beautiful code and make little bits of it uglier but faster." --The JavaPerformanceTuning.com team, Newsletter 039.