I have a 14' frame with a 28" Gammill that I love. I bought it used from a deceased friend's family, but in my research had decided on a 12' frame and a 24" arm-at least. I think you will be disappointed in the 8' table for the reasons others have given. One of my friends with the same Gammill as me but a 12' frame has her's set up diagonally in the bedroom she uses--allows her plenty of space front and back and able to move around one end. Another friend also with same Gammill and a 12' table has her's in basement and since she dislikes doing pantos and rarely works from the back, has very little space in the back and one side.
Don't worry about the dealer being an hour away--with a long arm set up (think this may be true of a sit down machine too). You rarely would take a long arm to the dealership--they are so bulky that the techs either walk you through the repair (I've even replaced the power source chip in mine with the Gammill tech "holding my hand" via telephone) or they send a tech to you. What's most important is how responsive they are to help calls! Gammill does a very good job at that--both my "local" dealer (3 hrs away), my "local" tech--20 min. away, or the Gammill factory.