hey Clegane, welcome to the forums
I've been playing Gondor since the Return of the King came out and recently I've been using a list like this one at 600pts. It's been pretty successful so far.
WARBAND 1 - 228
FARAMIR
HORSE, HEAVY ARMOUR, SHIELD
X6 KNIGHTS OF MINAS TIRITH
SHIELDS
X 6 OSGILIATH VETERANS
SHIELD
WARBAND 2 - 92PTS
DAMROD
X9 RANGERS OF GONDOR
WARBAND 3 - 151PTS
CIRION
6 WOMT SHIELDS
6 WOMT SPEARS
WARBAND 4 - 129PTS
BEREGOND
6 CITADEL GUARD 54
SPEARS
5 CITADEL GUARD BOWS
At 800pts you could add in Imrahil and place him on a horse, and change the knights of Minas Tirith for Knights of Dol Amroth. I'd also dismount Faramir and place him with a larger contingent of veterans. As for 1000pts, you definitely want to be running either Boromir Captain of the White Tower or maybe Gandalf the White, as he does fit in thematically with the force
You might also want to add in Guard of the Fountain Court, I've been getting more of those recently so I can field a solid warband of them