Fixing or Tweaking Setup

[iproduce]

Hey ... Some partners and I are having a studio built and right now we have equipment setup in another department as of now. So When it gets finish (the final building), We are planning to buy more equipment. I wanted to know what was recommend and etc. Below is what we currently have.

iMac G5 Tower
Eurodesk Mixer 32 channel with talkback
Rockit Powered Monitors
Audiophile Firewire
Mackie Control Universal
Microphone, Headphones and etc.
Cubase SX
MPC 1000
Korg Trition SE

Hence I am buying 1 or 2 extenders for the Mackie Control universal I am going to need more midi ports and the audiophile has just 1in/1out. I am going to need me any recommended. Also .. The setup we have right now is kind of crazy.. it works BUT I will need to get it just right for when the building opens because that is a must. Right now I have the audiophile rcas going into the monitors and into the mixer and the mixer also going into the mixer. But that takes out my talkback button which needs the Aux how do I fix that. Im going to need the talkback button hence there will be a soundproof booth.

Also is there any equipment anyone recommend me adding on to my studio

Thanks