IMO, the un1tec barrels from Lucky are the way to go.
1) a single un1tec barrel with the back is circa 127 grams - that's very light for a barrel that's not made out of carbon fiber (for example, the DW barrel with a freak insert is about the same weight).
2) It's accurate and if you choose a dust finish you don't have to worry about scratches as much as with other brands - really strong. I drove mine into a concrete wall quite hard - the scratch is almost nonexistant.
3) It's inexpensive and good quality.
4) You can choose one or two or three different bores. Trust me, you really don't need more.
5) If you ever switch to a marker that has different barrel threads, a new threading sleeve for the un1tec will cost you the equivalent of two supersized meals at Burger King.
I owned a few barrels so far. Before I got the un1tec I owned a full freak kit, ditched it and I'm really happy with my current barrel.