First question first.The spinner sprayers tend to stop spinning when the roots hang down and fill the res and then the water just dribbles out so they are ok as supplimentals but you need the others also.
Second question about the grow tent.I have a few options to give.
1.Yes you could use multiple tubes even daisy chained together or find the larger longer tubs and make a bigger unit on the same principle.
2.Get a 4x4 flood table and a 4x8 pice of 2 inch foam sheeting,some 1/2 inch pvc,some hose,some 1/2" inch T fittings,some 1/2" end caps,a threaded 1/2" T,2 90 degree 1/2 " elbows and some misters and some 1/2 inch hose.....
Set the table out and then cut the foam sheet to size so it will just fit into the top of the flood table.The table is slighly tapered so make it fit snug.Then layout how you want your plants preferably in straight rows lets say its a 4x4 table with 4 rows total 16 plant sites.Your gonna make a manifold from the pvc pipe,Tfittings,and the Elbows..You want to cut 4 runs of pvc pipe that will fit across the tray about 1 inch up from the bottom(you will trim as needed.Put 1, 1/2 end cap on each pipe that 1 end done.Now on the opposite end you will be creating a manifold distribution line from the pvc pipe and fittings.Stcik a 1/2 inch T fitting on each pipe end except each eand pipe that gets a 90 degree elbow so it ends the line into that end pipe.Now cut to size little extra pvc pipes to connect each T fitting in a row.Somewhere in the middle insert the threaded 1/2 inch pvc fitting with the T pointing up instead of towards the other pvc pipe ends.You will screw in a 1/2" hose barb that has 1/2 inch threads on it to this fitting.This allows you to hook your hose from your pump in this.Make a tight 1/2 inch hole in the foam for your hose to come out and then it goes to your pump.In each of those 4 lines drill a small hole for your misters place 1 mister so it is bewtween 2 net pots one on the left and the right .Your Flood table will probably have 1 or 2 drain sites so just run those to your res for drainage. You now have a flood table converted into an aero table. They also make custom fit plastic dome lids for these tables you can buy it and use it instead of the foam sheet but it costs more.
3.You can make a smaller version of my 32 and bigger aero setups using 2 8 foot pvc fence posts and some 1/2 inch pvc and fittings.Cut the 2 posts in half so you have total of four 4 foot chambers.Drill out 4 holes evenly spaced for 3 inch netpots to fit in.Secure fence post end caps to each end waiting to close the last side as you will add mister lines inside.At one end of all the posts dril a centered 1/2 inch hole.You will make the same manifold line as described on the flood table above one for each post.Inside each post a length of 1/2" pvc pipe caped on 1 end.Add your misters and finish the manifold and there you have a simple aero /NFT grow setup for 16 plants.I can custome build thise unit if anyone needs it,Can be modified to less sites or more in varies sizes to fit your needs just pm me.These are really cheap if you have yur own pump and res tub or I can supply it all together.Just pm for questions