Unless you have shatter shields (only Saruman has access to it for good), bows are quite useless, IMO. Okay for getting one or two last minute wounds and maybe driving the opponent back out of charge range, but not good to rely on. Bolt throwers seem potentially devastating, but not had a chance to use any.
Since he has SO much infantry, take a load of knights and dol amroth knights and show him what a charge really is - you strike first, get 8 attacks per company (not including fight difference) on the charge (as well as a possible unstoppable charge) and he has to do 2 wounds at a time to kill each of yours. Then, there's a chance that you get to charge back in again!
If your games are a simple "kill them 'til they're dead" scenario, then you'll want a load of cavalry, saruman (to remove shields and preferably in an infantry unit for added protection), a unit or two of archers to niggle away (D5 protection for Saruman too and they can target whomever you shattered the shields of that turn - he also protects them from being charged 50% of the time) and your avenger bolt throwers. Once you have a solid core, you can take a few more epic heroes to allow At the Double! moves and to provide might - good choice in faramir, pippin is also cheap and can protect you.
Tactics: Take out the Warg riders with shooting because they'll ruin your glorious charge. Use shooting/spells of ruin to take out as much of Khamul's unit as possible, before he's in range to bounce the wounds onto you. If it's the Betrayer, you could do the same but to reduce the number of re-rolls he'll get. If Faramir has just one point of might left, don't be afraid to epicly sacrifice him (this has won me a combat by a landslide before - instead of losing my entire unit, he died and I destroyed theirs. It was Haldir in Khazad Guard, but you get the point...). If a formation has one or two models left in a company, don't be afraid to shoot them to drive them back. Avoid using might around Gothmog - rely on killing the troops around him, rather than him. Get your archers into a building (or other terrain if there are none) if possible - D6, 7 or 8 on your archers = Epic
A vague outline for a list:
Faramir - 90pts
Archers - 2 companies - 60pts
Archers - 2 companies - 60pts
Knights of dol amroth - 4 companies - 200pts
Avenger Bolt Thrower - 2 companies - 100pts
Knights - shields - 4 companies - 120pts
Knights - shields - 4 companies - 120pts
As a starting block, that's 750pts. I've left out Saruman because he is a LOT of points in such a small game. In those 250 points, you'll want at least 2 more Epics to lead your knights - Peregrin is only 75pts (leaving 175 more) and gets bonuses for being within 6" of Faramir as well (cavalry all charging in one area anyway). With that, you could ally in another hero (one of the monkey twins to save points or Boromir for his juicy rules and stats) and/or get some more troops in.
Hope that helps illustrate some of my thoughts!