If you're going to play an elf archer cleric, the only prestige classes you should even consider touching are Templar and Sacred Exorcist. (Mettle is a wonderful ability).
Full clerical spell progression is far better than any of the abilities you'd get out of the other books. Which would you rather be able to do--fire a bow in melee without provoking an AoO or cast Flame Strike, Raise Dead, Persistent Divine Favor (be sure to use a Bead of Karma), etc?
That being said, however, consider coordinating with your friends to come up with some tactics. What if you all bought gems (or Helms--DotF) of True Seeing and walked around in an enlarged, heightened Deeper Darkness spell? Or if you cast Blindsight on the whole party and did the same thing? How about if you all had expert tactician then? What kind of synergies could you all get working together? Ordinarily the S&F Dual Strike feat isn't that great but what if everyone in the party had it?
Think about how you'd respond to situations: What if you run into fog? Monsters with blindsight? Tremorsense? Incorporeal creatures? At that kind of level those are things you can expect to come up against.
You should also consider purchasing equipment with other people in mind. What if everyone in your group bought two arrows of slaying and gave them to the archer? You'd have an arrow of slaying for everything you might encounter. What if everyone bought 50 +1 x-bane arrows. You could have a bane arrow for every foe you encountered too. The cast GMW on them (using the bead of karma) and you have effectively +6 arrows (bane arrows function as if they were +2 more than the normal enhancement bonus against their targetted foes) that do an extra 2d6 points of damage.
Think about tactics that work in tournaments better than home-games too. Sunder may trash loot in a home game but do you came about that in a tournament? Get Improved Sunder, adamantium weapons and a clvl 15 scroll of GMW (heck, make that a clvl 15 scroll of Chained GMW and get all of your weapons in one hit) and then go to town on your foes weapons. What about Mordenkainen's Disjunction. Ordinarily you'd be hesistant to use it on your foes but since looting them doesn't matter, get your wizard a scroll of it. When an opposing party shows up buffed to the hilt, hit them with Mord's Disjunction!
Think about consumables too. If you're playing that cleric, get a scroll of Persistent Divine Power (8th level, clvl 15). You only need to roll a 2 in order to successfully use it when your Bead of Karma is working.
Olgar Shiverstone said:
Judging from the some of the discussions over in the archer thread, consider an archer character.
Wood elf (+2 Str, +2 Dex), take a level of cleric (elf & war domains) for free weapon focus, point blank shot, and access to true strike, then a bunch of fighter levels (all archery feats, weapon specialization), then go into one of the broken archer PrCs (OOBI/PA/DWS).