I have a 3x6 table which has been lots of fun. I wish I had two 3x3's instead, because that thing is a bear to clean, move around, etc. 4x8 I would feel that even more. I also grow in three turbo gardens, which are 22x30 tables. But you'll have fun. You have enough light for your table and that's the most important thing (well, after space). I grow in hydroton, haven't really tried anything else. Hydroton is a PITA to clean when it's new, I've been using the same stuff for years. I've grow large plants in individual pots on the table and also filled the entire table with hydroton and planted 40 clones directly into that. Very successful either way. 80 gallons is a nice size reservoir, you can flood deep (get riser extensions for the overflow fitting so you can flood to the max). I recommend synthetic nutrients, I use Dyna-gro. Also Dutch Master Gold Zone will keep your plants' roots nice and healthy. Aeration is also critical, I use 4 airstones in a 75 gallon reservoir. I live in the North and don't have to worry about reservoir temperatures but if you or your grow room are located in a warm climate you'll need to keep track of your res temps. Under 70F is good. Change out you reservoir every two weeks, keep your pH between 5.5 and 6.0 and the rest is easy. Lots of info on this site, good and bad. Welcome to Rollitup.