Venus transit (6/2004) and filters

I was reading a review of a Vixen scope and the reviewer stated that using Baader solar film (which I have) and a 8-10 angstrom calcium filter and a Day-Star .5 angstrom T-scanner would all be helpful for solar observing. How essential or beneficial would the calcium filter be? Where would I get one? (I reckon I can look up the Day-Star T-scanner before I ask any questions on that, though any information posted would be helpful to me and future transit observers).