Hi petr,
I too would be interested to hear from other readers what the main and sub-command dial to housing interface is like on the D70 housing. I have been using the Ike N80 housing and find that the lever/command dial interface is difficult for me to use. Looking at the pictures on Ike's site, it looks the D70 housing might have a housing dial to camera command dial interface that should be easier and quicker to use. I'd love it if someone could help me here too. Unfortunately, no reteail store in Australia stock the Ike housings for me to go and take a look for myself.
Petr, I can tell you that you need the 5503.55 dome for the 18-70 lens (check http://www.ikelite.com/web_pages/2port_nikon.html for other lens/dome combinations). I have heard positive feedback from others using this housing. Also, remember that you will need a +4 diopter to enable to lens to focus on the virtual image the dome projects and therefore make your pictures in focus.
I don't know about the Ike implementation of iTTL, it is possible that it will happen within the next few months. Even if you do get the housing without it, at least you will be able to use it in the mean time. The normal procedure would be to send it back to Ike for the iTTL upgrade once it is implemented.
HTH 