Fist: -1 to win fight, +1 enemy defense (or -1 Strength if you prefer...)
Dagger: +1 enemy defense
Hammer/Club/Staff: If you win the fight your opponent is knocked to the ground.
Axe: -1 enemy defense
Sword: Parry- after you lose a fight, you may force your opponent to re roll one successful to-wound roll. This may not be done for attacks of strength 6 or more unless your models strength is also 6 or greater.
*Two handed Sword/axe/hammer - -1 to win fight, +2 Strength. If fight is won on a roll of 6, opponent is knocked down.
*Flail - As two handed weapon with optional special attack: If the fight is won, they may choose to knock every enemy in base contact down rather than roll to wound.
Spear - no changes to SBG rules (possibly a bonus against cavalry?)
*Halberd - may be used as a spear or two handed weapon. Choose before resolving fight.
Short Bow - Orc Bow
*Bow - Bow
*Longbow - Elf Bow
*Crossbow - Uruk Hai Crossbow
*Musket - Uruk Hai Crossbow +1S, 30" range, alternate turn firing.
Throwing weapons - SBG Throwing weapons rules.
*Cannot be used with shields
Kept Shielding rules and Armour rules.
I never got around to working out prices, but these seemed to work fairly well, and gave some legitimacy to commonly underused weapons.
For the mercanary warband I used the following profiles:
Captain: Captain of Men
Champion: Captain of men, -1A, M/W/F :1/0/0
Warriors/Marksmen/Swordsmen: Warriors of rohan (with D3, as armour must be bought), Marksmen Have F:3/3+, Swordsmen are equipped with swords and have F4.