Sligh's alternate land source. . . . . .

[element98106]

Ok, I am playing a sligh deck at the moment. Now I don't want my entire mana base to consist of only mountains. I think by taking a mountains only approach, this will slow me down a bit. Anyway, I wanted opinions on what type of mana base you would run in this deck. Any comments will be helpful, thanks!

2x Ball Lightning
4x Grim Lavamancer
3x Orcish Librarian
2x Rathi Dragon

2x Breaking Point
2x Browbeat
4x Chain Lightning
3x Flame Jet
4x Incinerate
4x Lightning Bolt
4x Pillage
1x Wheel of Fortune
4x Seal of Fire

3x Barbarian Ring
12x Mountain
4x Rishadan Port
1x Strip mine
1x Wasteland

For a while I was running 4x wasteland. Wasteland with Pillage gave me the ability to deny multi colored decks a certain type of land. I just changed them to rishadan port's and haven't played the deck enough to figure out if it will be successful or not. I think the wasteland had better psynergy with the grim lavamancer, but not sure.

[silvernail]

I'd probably run mishra's factory over barbarian ring

-2x Ball Lightning
+2x Genju of the Spires
4x Grim Lavamancer
3x Orcish Librarian
2x Rathi Dragon

2x Breaking Point
2x Browbeat
4x Chain Lightning
-3x Flame Jet
4x Incinerate
4x Lightning Bolt
4x Pillage
1x Wheel of Fortune
4x Seal of Fire

-3x Barbarian Ring
12x Mountain
-4x Rishadan Port
1x Strip mine
1x Wasteland

+3x wasteland
+3x mishra's factory
+4x Mountain

This version runs 3 more lands instead of flame jets. They are pretty bland, and the deck wants 15-18 mountains (RE mana sources). The factories and wastelands do produce mana but they serve alternate purposes.

You are right about wasteland and grim lavamancer, so I'd change ports to wastelands again. Port is also mana intensive , in that it slows you down to port them continually. Wasteland has a similar effect, for non basics at least; and it does not take an extra mana each turn.

Factories and Spires over Rings and Balls comes down to recurring damage compared to temporary damage. Also with only 12 mountains the deck might not have 3 red when you'd want it. Even at 16 mountains, you'll be hard pressed to get 3 red, especailly considering Rathi Dragon ( I'd honestly run Rakdos Pit Dragon instead , but thats me).

Another reason Factories are likely better than Rings in this build is the Grim Lavamancer. He'll cut down on your threshold potential, effectively castrating your Rings.

[Shake]

I've found that sligh relies on a great deal of red mana, especialy with ball lightning, so I wouldn't put in more than 4 colorless mana producers.  I prefer the wastelands, but I supose that's a personal preference the barbarian rings are also pretty good for silver knights and COP red.  I definately wouldn't put in factories, too slow.  Actually you might want to re-examine your desire to put in non-basics at all.  I play with 4x fireblast, and sometimes with price of progress, at least in the sideboard.  Genju of the spires is a pretty good 1 or 2 of that needs mountains, too.

If you want to take advantage of the nonbasic lands, then I sugest you add cursed scrolls, cut the ball lightnings, and add more 1 drop creatures. 

It seems that what you're really looking for is more of a ponza scheme.  I'm not the best with that deck type, but it looks like a one drop creature, a little burn for their turn one blocker, followed up by rishadan port, wasteland, pillage, molten rain, etc. then ended with a finisher like avalanche riders, arc slogger, or rathi dragon.