Backup body or new lens?

[Csae]

So i'll try to keep this brief, my current setup is a 5d, 17-40, 50 1.8, a couple hot shoe flashes, and a good amount of studio equipement.

So far i've been putting whatever earnings into getting a decent studio running. Now that i consider that pretty much done im looking back at my camera and lenses.

And i've come across this little dilemma...

To buy a 85 1.8... or a 40D... a 40d would make for a awesome backup body to my 5d, with increased fps, and would turn my 50 1.8, into a 80 1.8...

Or i could just get a 70-200 f4L... i dont shoot 1.8 too often, and f4 on my 5d is shallow enough for my portrait work. Not to mention that i've been using the 17-40 so much im pretty used to f4.

But having a backup body would be something on its own...

*Shrug* What are you comments / inputs ?

nb: anything i'd buy, i'd buy used :P so consider used prices.

[Rooz]

you're defiantely short on a good tele. get the 70-200/4 imo. personally, i wont buy another body until video, live view and a flip screen are properly implemented.

[Visual Reality]

If you shot weddings I'd say get the backup, but since you do studio work with models I don't see it being much help.

I'd buy a 70-200 f/4 right now if Nikon made one, damnit.

[Rhys]

If you can cope with the lenses you have then I'd say get the body. A broken body could put you out of business. I see you're considering secondhand so business can't be that great. Make sure a broken body doesn't put you out of business and consider another lens next time.