I currently only use 1 Cleric to heal my entire party, Warden/Sent. i have done a few hard modes (FC and KB) on this team, and i may from time to time need extra healing, i have not decided to add in a chloro yet, but i am tempted.

As for my healing setup, i have everyone on a 3 slot Group healing frame using mouse-over macros and mouse sync. I have all of the healing abilities put on a numpad mapped bar, all primary abilities are 0-6, with all my aoe healing abilities on .7,8, & 9. I even use this build for raiding on my cleric as well so it heals a bit. Each toons has separate keymaps so i can turn them off and on at will. I also have a key map for my cleric to DPS and to not allow DPS, for elite fights/rights, where i need him to be able to strictly heal.

My Team makeup is:
1 Warrior (Reaver-Hybrid) (Staple 1.8 build)
1 Mage (Pyro/Lock) may add a Cholor Build.
2 Rogue (Ranger/MM or MM/Rangers) - Ranger/MM is more gear dependent then MM/Ranger currently within 1.8-1.9, which i currently lack HK gear.
1 Cleric (Warden/Sent)

So as i heal i follow the standard front load my Tank with Heals strat at the start the fight and heal as needed, watching for AoE healing as needed, when i need to AoE heal i just press the proper numpad key on my main keyboard to activate the proper heal on my Healer's computer.

DPS wise my guys pull between 800 and 1100 mostly wearing crafted and AH Purchase-able gear. So i usually am not within a fight that long.