I built a speaker kit from parts-express.com. The kit was complete with mdf pieces and all the components to build the crossover and speakers.
Basically I has to glue everything together, then solder the crossover and install the drivers.
Overall the speakers sound really good. I am very pleased with the way they sound and overall the kit went together really well. My only complaint is that the screws in this kit were pretty lacking, but you can watch the video to found out why I think that.