An LED headlight is the lightest, most versatile light. The batteries last a long time. If you really want a 'lantern', look at a Candle Lantern, sold by REI and other outdoor stores. It's pretty lightweight and packs very small. There is a variation that uses tea candles (smaller but available everywhere) that might be a good option as well.

The 'standard' Coleman mantle lantern would not be a good choice for touring. The mantles would not likely take well to rough roads.