Mountain Biking - What chainguide?

I am looking for a chainguide for my bike. Ive looked around alot, and havent really figured out which is the right one for me. Right now I have dual chainrings with a bashguard, but eventually plan to switch to a single larger chainring. Is there a chain guide system that can be used dual or single? I need it to hold a fairly large chainring.

Wait until you get the single ring. The dual ring guides could be run with only one ring but they won't be as effective as a dedicated single ring guide. Gamut, E13, MRP guides all are really good. The MRP G2 is a really good guide and will save you weight with the skid plate bash instead on a heavier crank mounted bash. E13 makes a similar guide but I've read some reviews and people say the MRP is much easier to set up. Gamut is supposed to be good but I am not very familiar with them.

Thanks. What about Truvativ box guides? They make a double and a single one I believe...

The have the Box-guide is the single ring guide and the Shift-guide works with a dual ring. They are the same basic design as the E13, MRP guides but I don't think it is as high of quality.