Your Choice.
Bluedog190,
I'm going to dissagree with the majority of the guy's here and say go for the 767.
The reason why I dissagree is your command WILL COME eventually maybe sooner than you think and when it does come it will be on the 76.
Also consider this you're transitioning to widebody one more tick in the box.
If it doesn't work out you can always go back to the E-190 As a captain ( Remember the type is growing in numbers you will fit in nicely as a direct entry command from a Widebody with no training required).
One of the best Captains I ever flew with told me " If your'e a good first Officer You'll Make a Good Captain" I'm now a Captain I agree with that. This guy was awesome of his 12,000HRS TT on 737 9,000HRS were as Co-pilot it wasn't his fault there was simply no movement in the company he was in so he just stayed there. But I have to say he was definately super to fly with I learnt alot from him.
As pilot's we don't necessarily plan to be F/O's for our careers unfortunately it does happen I was stuck there once it wasn't my fault it was just the way things happend after finally getting my command and being a Capt for a few years i'm about to go back to being in the right seat for a heavy jet
thats fine with me.
If its a Command you want then you must take the opportunity when it comes.
If it is progression on to a Heavy Widebody Jet then you should take it. Get it on your ticket. NO ONE is gonna hire you as a Direct Entry Capt on a 76 if your'e a Capt on a E-190 in any case.
I think I understand your situation being frustrated with being an F/O for many years with the posibility of finally getting you chance to be Capt well my friend if you want it that bad then you must do it.
As for immediate Career progression good things come to those who wait... My advice is go to the 767.
Your Choice,
Good Luck,
Pete77