I was thinking of Expedition Map, which lets you search for any land you need. It also happens to be an artifact ;)

Well now if you're running White Ethersworn Canonist limits your opponent to one spell per turn, and Scourglass is a one-sided board wipe for mana

This may be a crazy idea and it might not work, but what if I used Storage Matrix in conjunction with my Unwinding Clock? They can only untap 1 thing on their turn and all of my artifacts will untap on their untap step and I could choose to untap lands during my untap step. They would be forced to untap only 1 thing and I could untap everything. I probably won't use it, but I could. To be evil. >:3

Did I mention that Ethersworn Canonist would be forcing them to only 1 spell?

Maybe I can try using Urzatron? While I don't need a lot of mana for single cards I still need to get out my combos as fast as I can. Locus requires 2 of it out, but I'm not going to get Vesuva simply since I wouldn't wanna pay that much for what I'm getting from it. I could try running Thespian's Stage instead. With Urzatron I have to get 3 out and they will produce a bit less mana, but they don't come into play tapped. I could also just fetch another Cloudpost with an Expedition Map if I draw one. :l

Maybe Storage Matrix but if you want that type of effect possibly consider Stasis plus Unwinding Clock plus Seat of the Synod makes all their things tapped forever. Stasis isn't cumulative upkeep. Although, this would make your deck more control oriented.

Stasis would keep their stuff perma-tapped, but my stuff won't my stuff stay tapped forever too since both untap steps are skipped and Unwinding Clock doesn't get to untap my artifacts?

@Duskfell, Yeah, Stasis has no synergy at all with Unwinding Clock because Stasis skips untap steps and Unwinding Clock's effect only happens during untap steps.

My mistake about stasis. XD

Phyrexian Juggernaut is a card to consider. Infect kills indestructible, it is a must block and it kills in 2 hit with base stats. Cranial plating makes him a 1 hit kill against all deck( without platinum angel in play), even vs lifegain. It's my best finisher in my artefact deck, especially when I cast 2 for the price of 1.

I'm gonna do some more playtesting, but I found that Mystic Gate ended up being far too often. I'm going to see how Seachrome Coast fares. I'm also considering Azorius Chancery only because it could bounce back a Glimmerpost. Even then my experience with bounce lands is frustrating.

May I suggest Ancient Tomb, City of Traitors, and Grim Monolith? All would allow you to cast these spells faster and more on time.

If you are a fan of untapping Steel Overseer, you may wish to look in the general direction of Voltaic Construct ESPECIALLY considering that you have Cloudpost as a mana option.

I'll definitely consider adding in Voltaic Construct, maybe replace Etherium Sculptor with it since my posts should boost my mana enough.

If have some spare money I may get Grim Monolithand take out some lands. I'm not sure if I would run 3 or 4 copies, but that sure is a pricey card. If I find myself too tight on cash whenever I order I may get Basalt Monolith instead.

Have you considered Master Transmuter I have found that she is great mostly for protecting your dudes but also dropping dudes at instant speed plus she does well with Unwinding Clock for speed if that is your game at the moment. Plus Etherium Sculptor makes her cost a bit easier to handle. She can even save herself if need be. Just a thought like the deck though. Oh almost forgot Arcbound Reclaimer pairs well with Steel Overseer.

Master Transmuter looks great and Arcbound Reclaimer looks good too. I'll have to consider them. Phyrexian Juggernaut is kinda odd for me. On one hand I want to use Darksteel Juggernaut due to affinity and indestructibility, but Phyrexian can get rid of indestructibles (probably better off sideboarding him instead of main). On the other hand I want to use Phyrexian Colossus just because I love it, but it's impractical and Power Matrix would make the ability irrelevant.

The one thing I need to test the most is if this deck would be better off with 8 more colored lands rather than 8-post.

Well since you do play creatures there is always Thran Quarry, or since I don't really think its mana in numbers that you need just mana fixing for colors something like Shimmering Grotto might work out well, or heck Mox Opal since you will probably have metalcraft most of the time.

I don't play Legacy much myself, but do they ban any infinite combo pieces?

Specifically the one I'm thinking to suggest in place of your Etherium Sculptor's are 2-3 Grand Architect and 2 Pili-Pala which together make infinite mana of any color.

I do recognize that you only have the one card to abuse infinite mana with but I still think it'd be a good set up if you can make it work.