What box should I build?

Hi!

I´m know they aren´t the best, and most people talk crap about them.
But I run a sound rental in my hometown, and these were cheap and seem to please my customers that rent them mostly for private parties.
I had to invest more in the lighting too so when time is right I will buy more expensive sound.

But my biggest problem is the quality of the skytec bins, all the different plastics has to be re-tighten all the time and I think the bins feel to small.

I was looking at Cubo18, ok size and weight for transportation.

I´ve got 6x Skytecs right now (and 2 extra spare).
My idea was to build two bins, and move over both Driver and Amp to the new ones.
I´ve built bins before and got a workshop with all the tools needed, and a friend who sells wood (mdf) cheap,
I was going for 19-21mm thickness.

I want to build new bins anyway, in the future I could just change the drivers / amps for better stuff and sell these skytecs complete with original bins. So the new bins will be built seriously from the beginning.

I´ve got som problems finding any info about the drivers at all, maybe someone here´s got any suggestions.
The only info out there is:
Peak power 1000W
Power max. 500W
Power rms 250W
Frequency response 40 - 250Hz
SPL @ 1W/1m 119dB
Signal to noise ratio >80dB
Woofer 18 inch (45cm)
Top Hat Yes
Connector XLR
Dimensions 440 x 560 x 650mm

Any ideas about box build?

www.tronios.com/en/sound/speakers/subwoo...bwoofer-18-46cm.html