dudaindc
The each project is a specific design so if you are going to clone it you must use the same speaker drivers and crossover networks.
The STX is cheap enough but it is not top of the notch speakers brand, btw probably not available in USA ( I presume you live US ?)
Better off go for some good design with speakers available in madisound or parts-express, better quality and good price.
Pawel's work is top quality so it is good to learn how to build the speakers properly. If you need a hand there are people here who can help U.