i love my little sand master, its not the best by far but with a 9t brushless in it its a hoot to drive!
change the wheels and tyres to some wider buggy ones. FTX vantage ones are a great budget tyre for them.
only thing that will drive you mad is the poxy clip on body panels!
i run a 2s and 3s lipo in it, both from hobbyking i will get you links to them if you get one as the battery is loaded from below so space is tight. i went and searched for the biggest mah of each i could find that fitted lol
all in all tho its a great little buggy for the price! i would go for the kit version, cheaper and you can spec your own radio and running gear.
oh and get a RW pinion, stock is plastic and wont last long.