Help with my "itch" for a FF

[tt]

Here is a ff that I took today - uk otter

Lovely shot, bit of catchlight in the eye..

As mentioned - the 5D Classic / Mk I is a great camera and on the second hand market a good price - A 5D Mark III will likely depreciate in a year more than just buying a 5D Classic!
You've got two lovely lenses to try it with too -  24-105mm & 70-200mm f2.8l II. You'll lose the further "reach" of the 70-200 but gain a shallow dof of the shots.
Another option is just to line up a few things to shoot in a weekend, and hire a 5DMkII.

As a wedding assistant do you get to use some of the primary photographer's equipment or is it all BYO?

[carlc]

I prefer to use my own gear.  I have rented some equipment from Lensrentals when I feel there is a need outside the items in my bag.  That is how I feel in love (and later bought) the new 70-200mm f2.8 IS II.  And I am thinking that is exactly what I will do when LR gets the new 5D in stock.

This is the same way I felt when I had my new 1967 GTO, I loved it but was eventually tempted by the '69 Grand Prix.  Traded and have never forgiven myself.  My 7D is the same thing, I love it but there is this dang itch for a FF.

Thanks to everyone for their help.  So now instead of more advice, just send money!!!  LOL