Noob seeking test equipment recommendations

My first DIY project will be to build new enclosures for a pair of Cerwin Vega AT-15s. As part of that process, I would like to be able to test individual drivers, crossover components, and the loudspeakers as assembled units.

My equipment currently includes a laptop loaded with REW, a UMIK-1, a Dayton DATS V3, and a digital multimeter.

What other equipment and/or software do I need in order to optimize the performance of the AT-15s?

Thank you for your recommendations.