ADvice for duo setup for dailys

Looking for a bit of advice here:

My main is a 70 pally, currently resto specced, but sometimes I'm prot with him -- Neither of these setups are good for doing dailys that involve killing.

Now, I got a second account with either a 70 hunter or a 70 warlock that I want to use to fix that.

Which would you think is the better to play as the main character?

I was thinking that sitting on the dps class with a few follow and heal setups for the pally would be ok -- However:

a) I would have to switch alot to the pally to pickup and hand in quests as well as to talk to people as it is my main
b) The pally would do NO dps at all at this setup, as he is melee based.

So, if i opted to go for the pally as main with the dps as a 'boxed' character - How would you recommend setting that up?

EDIT: One major constraint is that if possible I do not want to "mess up" the key binds and setup of the pally - as he will be played solo frequently, the DPS class will only be played as DPS in the duo setup, so can do whatever with it.

Hope to get some thoughts and advice!

You can make an extra bar on the Paly and DPS. Leave it empty on the Paly and fill it with macros/spells on the slave (say, binds F1 to F12) and do not pass the rest of the normal keybinds so you can use the Paly without using the DPS.

That way you can keep the Paly as the main and heal and do DPS with the slave pseudo-independently.