The right decision 300 2.8 or 400 2.8 with the 1DMIIN

Hi,

I'm a Freelance Sports photographer in the Netherlands shooting with 1DMII. I don't know what to decide. Go for the 300mm IS 2.8 L or the 400mm IS 2.8 L. I now have the 400mm from Canon to try it, its realy a great lens but, heavy ...

If I go for the 300mm (with 1.4 and 2.0 extender) it's less heavy and I save 3000 euro. I have less DOF, but I think the 300mm (with extender) is also raisor sharp.

Please give me some advice and guidance. Thanks in advance .......

--
CU,

Rob Jelsma
look @ http://rjelsma.fotki.com/portfolio/sport/ for my portfolio