To be honest, your collection is better suited for SBG than WotR; you've got too much variety. But never mind, let's see what we can do.
We'll start by combining the Galadhrim, like you suggested, into four companies. If we give them shields, that's 200pts and you've got a nice, solid core to your army.
Sticking to the theme of big formations, let's get the three companies of Rangers. Also, for both thematic and competitive purposes, I'd advise taking Faramir as well (if you have him). He's very cheap and effective.
Going back to the Elves, we'll get all the Galadhrim archers in one formation. Altogether that's now 480pts. I'd like to get six companies of Riders of Rohan, but unfortunately there's not enough "ally points" left. Instead, how about four companies of Galdhrim Knights? Finally, add Haldir for your leaders.
Haldir - 75pts
Faramir (allied) - 90pts
Galadhrim Regiment, shields, four companies - 200pts
Galadhrim Archer Regiment, two companies - 100pts
Galadhrim Knight Regiment, four companies - 200pts
Rangers of Gondor, three companies (allied) - 90pts
Totals: 755pts, four formations, thirteen companies, and seven Might.
I realize that this army is 5pts over. Hopefully the tournament organizers are quite liberal... anyways, I hope I helped.