DedWards

Did a rough design of a deck you might like:

http://www.mtgvault.com/dedwards/decks/do-not-waste-it/

Wheel of Fate?

Ancient Stirrings can help "search" for Liquimetal Coating... or any other Artifact or a land.

I initially thought so too, but after much testing, I found Bolts to not be very important in here. I'm even thinking of dropping the one I have for a fourth Mizzium Mortars.

You need at least 3 Open the Armory. Then you can replace the unnecessary draw with kill.

Thanks for the suggestions. I actually designed this as a starting point for a friend that wants to run Servos. Something he can work towards and modify as he sees fit. I will get him to read your suggestions.

Triumph of the Hordes - Another source of surprise Poison in green.

Magnetic Mine - A way to get more out of the Liquimetal Coating and artifact destruction.

I have, but it doesn't do much unless you can guarantee 6+ damage. Plus, you don't need more land destruction than what I already have in here. The deck is about controlling the opponent's mana, not destroying it all.

Cards that can manipulate the number of time counters on your Suspended cards:
Clockspinning
Timecrafting
Fury Charm
Rift Elemental
Timebender

Reliquary Tower might be a better fit than Library of Leng. Being a land makes it more difficult for the opponent to destroy, it doesn't cost you mana, and it'd make this deck Modern legal (if you care about that).

A note on Ardent Plea's Cascade: it hits more than Ethercaste Knight. It actually hits all of the following:
Ethercaste Knight
Library of Leng
Evermind
Hundred-Talon Strike
Peer Through Depths
Reach Through Mists
Veil of Secrecy

Cascade stops at any nonland card that costs less than it, not just creatures. It's how the Living End decks combo off.

The amount of mana isn't the problem, obviously. The problem comes from where the Hymn is when you cast Reiterate. If it's not on the stack, Reiterate can't cope it.

Small problem with Reiterate here, you need 6 mana to pay for it with its Buyback, which Hymn does give, but that means the Hymn already resolved, so it's no longer on the stack for Reiterate to copy (it'll be in the graveyard). The only way to remedy this is to cast a second Hymn, then Reiterate, but that requires 8 mana, 2 for the second Hymn, and 6 for Reiterate.

I tried to do a similar combo with Izzet Guildmage copying Lava Spike after I spliced Desperate Ritual onto it. To combo off, I needed the Guildmage to be on the battlefield already, then generate 6 mana. 1 for Lava Spike; 2 to Splice Desperate Ritual onto it, and 3 to copy it will the Guildmage while Lava Spike was on the stack.

It is "slower" than Omnath, but it's also the closest thing I could find that works in a similar manner to Omnath. I initially looked for similar effects because I wanted a way to carry over the mana from Braid of Fire, and Omnath was a no go because of the difference in the colour of the mana.

Gemstone Array; while not as efficient as Omnath; is another way to hold onto excess mana.

Phyrexian Metamorph can copy Puresteel Paladin, or or any equipment already on the Battlefield, if needed.

Etherium Sculptor makes artifacts cost {1} less, opening you up to more options for equipment.

Guul Draz Assassin?

Hedron Blade is a must for the sideboard.

Scrounged Scythe (Harvest Hand transformed) gives the equipped human Menace.

True-Faith Censer gives +1/+1 and vigilance. If equipped to a human, it gives an additional +1/+0.

You can only Donate to one person. I was thinking of Paradox Haze in a similar way. Donate Rust Elemental, enchant the same opponent to speed up the Elemental's damage effect. Or play Braids and whomever you enchant has to sacrifice twice as many permanents to the point where they have next to nothing, they can't sacrifice Paradox Haze because you're the one that owns and controls it.