recommend me a 29er

Im looking to build a 29er fixed gear as an icebike.
But i have a few questions.

How much movement do i get if i have a eccentric bb?

Has anybody here tried one of these double cogs:
http://sheldonbrown.com/harris/fixed-sprockets.html#dingle
are they any good? i was thinking about geting the 17/21 and using it with a double chainring. i was also thinking of getting a flip-flop hub so i can have a double freewheel on the other side so that i can do some singletrack in the summer.

Can anyone recomend me a good 29er frameset for a reasonable price. I think im gonna go aluminum (because of the salt in winter). I want atleast a front disk brake mount.
I had my eye on this one:
http://www.psyclestore.com/product_info.php?cPath=26_45&products_id=184&osCsid=d0d1b09ccdd7b0453243248a042228f9
but at 350$ for just the frame i thought maybe i could find something a litle cheaper.

Why not go with a frame with forkends like the Redline Monocog and not worry about an eccentric BB?

plus it’s like 200 bux less.

How does chromoly hold up to slush/salt?

It holds up just fine, as long as you take care of it. Just apply Frame Saver and be on your way.

i have a raleigh XXIX with the eccentric BB. it’s worked pretty well. have to snug it up some times. there was about 2 links worth of adjustment, which wasn;t enough to run any gear ratio. had to go through a little trial and error.

I’m going to be using a monocog as my ice bike this winter. I’ve got it set up with a disc brake on the front and a fixed (tomicog)/free hub on the rear, and two coats of framesaver. Now all I need is a set of quality studded tires.

The only drawback of the monocog as a winter bike, IMO, is the lack of fender mounts. I’ll be using a strap-on.

hiooooooo

Does anybody know the chainline for each of those sprocket on the Surly Dingle?