About 4 months ago I bought a 70-300 Tamron lense and so far it has served me well. Now that I am seeing the limitations, however it was a cheap lense bought to get me into longer range photography & motorsport before I bought something expensive. Not sure which way to go now tho. I currently shoot with a 350D, but I have just sold my MX5 trackcar and have some cash to spend on my photography, up to £1300 to help me get more advanced. I have a couple of options: 1: EF100-400mm L IS USM to use with my current 350D and have a few quid left over for a new kit bag/back pack & an A3 printer 2: sell my 350D, change to a new 40D body, Sigma 100-300mm f/4 EX DG HSM(or similar), kit bag/backpack & an A3 printer. Most of what I shoot is motorsport, espacially close action sports like rallying, motorcycle road racing as well as circuit work. Whatever I go for, I also have the standard 18-55mm kit lense and a 10-20mm. I have started to get a bit of interest in my shots, and had a couple published in local motorsport mags, so I want to be able to move up to the next level. Would either of the above be suitable for this, or what would you suggest? Thanks in advance.