echo rims and coloured spokes preferably pink or green (i know you can get them in these colours with bmx but not sure about 26 wheels), and new hubs (with fixed rear)
all my bikes xc , dh , 4x and dirt jump as well as trials have been custom built with the exception of my first xc bike.............so with out a doubt i would go for custom build all the time, spend a bit more to get what you want