MTG Salvation

Concerted Effort

The best one I have found so far invloves using Guardian of the Guildpact, Enemy of the Guildpact, and Mistmeadow Skulk. Barring mass removal, your creatures can only be affected by low-cc artifact sources (or a Moonlaced low cc creature).

Of course you can always throw-in Skyhunter Skirmisher.

Any other cool combos?

Courier Hawk, Serra Avenger Trample is the tough one for white/black unless you want high cast or enchanments.

Beloved Chaplain, Angelic Curator, Auriok Champion, Paladin en-Vec

Here's cheap trample but at a cost Hunted Horror

Cairn Wanderer could pull double duty in this deck

Why not Akroma, Angel of Wrath and Commander Eesha, unless you only want low cc cards.

You are still weak to instants at the start of upkeeps.

Low cc
Beloved Chaplain
Mother of runes
Thoughtweft Trio
Slivers

High cc
Akroma, angel of Wrath
Akroma, Angel of Fury

Concerted Effort fits neatly into r/g weenie beatdown... Lots of cheap weenies with fun abilities that get scary with a mass creature pump on the swing with Mirror Entity or Agrus Kos.

Quote from sawbladex

You are still weak to instants at the start of upkeeps.

That will always be a flaw in the plan. It is unavoidable. (unless you throw in a Devoted Caretaker)

As for trample, you can use equipment.

For Mono-W in Extended:

Moorish Cavalry and Lodestone Myr grant trample.

Dust Elemental brings Fear and Flying.

Pristine Angel gives protection from all colors and artifacts, and if it has vigilance, it probably won't be tapping anytime soon.

Graceful Antelope and Hillcomber Giant lend out Plainswalk and Mountainwalk, respectively.

Other combinations:
Riftmarked Knight: Protection from W(eventually) and B.
White Knight: First Strike and Pro B.
Silver Knight: First Strike and Pro R.
Auriok Champion: Pro R and B.
Spectral Lynx: Pro G.
Mystic Crusader: Pro R and B with the possibility for Flying.
Paladin en-Vec: First Strike, Pro R and B.
Voice of All: Protection from any one color, Flying.
Foothill Guide: Pro Goblins.
Dragonstalker: Flying, Pro Dragons.
Kitsune Riftwalker: Pro Spirits and Arcane.
Needlebug: Pro Artifacts
Mirror Golem: Pro chosen card type(s).

Hope this helps.

And the White Akroma doesn't make much sense, as her Memorial does it already.

well, if you really just want protection from all colors in mono white, there are the 5 voices Voice of Reason, Voice of Truth, Voice of Grace, Voice of Law and Voice of Duty. Lots of extra flying, but it works.

Or you can use Voice of All to have a color relevant match up.

Order of the Stars gets you a 0/1 Defender with Pro-color-of-your-choice-when-it-comes-into-play for just W.

Its in another color, and it has a very high mana cost, but Petrified Wood-Kin.

Aerial Responder will give all your creatures flying, vigilance, and lifelink and is cheaper than many of the angels