My first thought is you may want a varifocal model for this so you can easily zoom to the appropriate distance and keep it in focus. Though you could probably achieve the same thing with a fixed lens model, you may have to break the glue on the lens and refocus it closer. In that case I don't know if 6mm would be adequate lens or if 12mm would be more appropriate.
Going with varifocal lense dome cameras. I was just thinking if customer would also like the pos feature. I haven't done a pos setup yet, so this would be my first. Plan on using the 2732F-I.