Buying/using ferrites of an unknown mix is a waste of time and money.
As for snap-ons, they are good if using on antennas/coax already installed. If installing a new antenna/coax, toroids are the way to go. There is also the durability factor of the snap-on plastic casing after some time subject to the elements.
As recommended already, read K9YC papers and purchase some FT240-31, FT240-43, and if you go into VHF consider some FT240-61 as well. For LF RX only I used a TDK N30 toroid.
As for a vendors, I've purchased from both Mouser and Digikey. Mouser is a little cheaper.