I'd suggest an Elf Cleric of Corellon Larethian. Domains: Elf and Magic.
Being an Elf grants you proficiency with bows as well as the longsword or rapier. You could even grab one level of Wizard for Mage Armor, Shield, Scribe Scroll, and a Familiar.
Elf Domain- grants you free Point Blank Shot
Magic Domain- Lets you use arcane items. (Useful since your party lacks a wizard or sorceror)
Stats: STR 14 DEX 20 CON 8 INT 16 WIS 17 CHA 16 (or STR 10 CON 14 CHA 14)
The low Con shouldn't be a problem, as you won't need to make as many Concentration checks or take as many hits as a melee cleric would. To offset this, max out ranks in Concentration.
Your high Dex will allow you to use a bow with great skill, as well as add to your AC. Stick with light armor. Later, try to get a Mithril Chain Shirt and/or Mithril Buckler, or armor enchanted with the "Nimbleness" property. This will keep your Max Dex Bonus high and your Arcane Spell Failure low (which is useful when using those arcane scrolls). Find or buy a Wand of Shield to raise your AC even more.
Raise your DEX and WIS with ability points.
Feats: Reach Spell (useful for healing from across the battlefield, plus your high dex will boost your ability to hit with the ranged touch attack), Dodge, Improved Initiative, Far Shot, Precise Shot, Rapid Shot, Shot on the Run, Extend Spell, and Persistent Spell. Possibly Weapon Finesse (rapier) if you find yourself in melee a lot.
Hang back and let your Fighter and Paladin close to melee. Use your bow and offensive spells to rain death from afar. Dart in when needed for healing and buffing.
** To increase your combat effectiveness, at the expense of a few levels of spells, consider going Half-Elf Cleric with 4 levels of Fighter (for Weapon Specialization) **