DUB SHOWS - need help with GEAR

[kingdom]

Greetings all the way!
Hands down to earth, I feel like I've come to the right place for asking questions and share my love for this music.
I am a long-time roots lover, rocksteady fanatic and skanking addict, foundation-deejay with a strong message spreading a positive vibe.
Then I visited a Jah Shaka dance some years ago during a trip to the UK, and it has inspired me to get deeper into dub music, which eventually brought me here. I really wanna bring it on and play dub shows (deejay-wise). Since no other musicians in my area are familiar with this type of music, I turn to you for advice. I do know how to string up a sound, but I have no idea of the equipment used in production / for dub.
I have a Denon 4 channel DJ mixer, two technics turntables, a korg kaospad and a mic. That was more than enough for down-to-earth spiritual roots shows, but I need to buy new gear if I wanna play around with dub.

Which equipment would you recommend in particular for playing dub shows?
I thought of a 12 channel mixer, but been pointed to those with 24 channels...
Is a something like this already over the top?
http://www.thomann.de/gb/behringer_xenyx_2442_usb.htm
What sort of preamp would you recommend?
Do I still need my Denon mixer for shows if I buy the new gear?

I am glad for any serious word of advice, feel free to share your insights.
Oh, and regarding the preamp, I don't have the knowledge of building one myself (yet), it's maybe something that can be done in the future, but for now I would prefer to buy one just to check it out and familiarize myself with the sound I really want.

Thanks for your time and help. Bless up!

Dom