I'm an amateur photographer and want to expand my photo equipment to a telephoto zoom lens & a wide angel lens (for a Canon EOS 300 SLR Camera), but don't want to spend a fortune. Which brand should I buy? Sigma or Tamron? I'm thinking about the following lenses: - Tamron Autofocus 70-300mm f/4-5.6 LD 1:2 Macro Lens - SIGMA LENS 28-300mm f3.5-6.3 Compact Aspherical Hyperzoom - SIGMA LENS 70-300mm f/4-5.6 DL Macro Super SLR Camera Lens - Tamron Autofocus 19-35mm f/3.5-4.5 Wide Angle Zoom Lens Which are the best ones? Or would you recommend something totally different? And is the "BOGEN 3021BN Manfrotto" Tripod recommandable?