Lewis- post a basic sketch of the plans you have in mind. It would give us a starting point. Include the track type you have and type of switches, etc. Hand-drawn is fine. We won't critique your artistic skill 
If you have issues with the software you are using, SCARM has a free download that is pretty simple to use.
I like Lew's suggestion of a bridge to connect the tables as you walk into the space too. It will give you more operational variety. Swing bridges are better IMHO. Either up or down works depending on your space. Lift-outs need to be put someplace when you remove them as opposed to just hanging there by the hinges. More complex to wire too since you will need plugs to disconnect the wiring each time. Several guys on the forum have done swing out gates too.
If you want multiple levels, consider not connecting them, or at least the uppermost one. Simplifies the design a lot. A train or trains, (with a passing siding), can just travel on their merry way while operations happen on the lower levels.
Seriously re-consider the 4X8 tables too. I'm 6'5" and I can barely reach the back of my 4X8 section.
Bob
