Greetings!I currently have a self-contained head that I'm preparing to replace with a new Lavac Zenith head and Lectra/San sanitation system. My neighbor has been through just about every head imaginable, and his newest aquisition (46' Wauquiez) has two of the Lavac Zenith heads, which he believes is the finest system available, given their simplicity and reliability. I too have had my run-in's with marine heads, and I had never heard of Lavac, but I have to say that I'm convinced as well after spending a week on their boat.In any case, my installation will require that the Lectra/San be mounted above the head discharge. I assume that a vented loop will be required so waste water does not flow back to the head, however must the loop be a certain height above the toilet discharge or Lectra/San? I only have perhaps 2' of space to work with. Is there a specialized vent for this purpose, and must it be vented outside?Also, believe it or not, I have no space for a holding tank. Is this an issue, other than my inability to discharge in specified "no discharge" zones, such as the Florida Keys reserve?Lastly, any tips on the installation would be immensely appreciated! I'm completely "head-less" when it comes to marine sanitation!Thanks in advance!