PVC Hydroponics construction help

Hi, Im planning on building a system made up of 2 4-inch PVC pipes for an indoor garden.
The way im making this system, it can be either a Flood/Drain system or a Nurient film system.

specs:
2x 4-inch pvc pipes with 5 3-inch holes in each of them for net pots, 10 pots total
10 gallon resvior (probably or less)
Pump w/ 1/2' tubing going into one side of each pipe.
Drain pipes will be of 3/4 inch pipes leading into a 1 inch pipe and back to the resvior.

I have 2 problems,
what is the best way to cut the 3 inch holes into the thick PVC pipe?
and, I couldnt find any fixtures to effectively seal the 3/4 inch pipes that are connected to the 4 inch pipe both on the cap underneath the pipe (rounded surface).

I was thinking i could use rubber grommets to seal them but im worried about leaks. If theres no fixtures avaible to do this, what is the most effective sealant?

I've included a couple MSpaints of how i want this to turn out, also i am not growing marijuana

Please note the first Drawing is an earlier picture, before i decided to change the drain pipe. In the second picture, the pipe going to the bottom of the larger pipe is the Nurtrient Film drain pipe, with a open/close lever on it, so i simply open that when i want to switch modes. The grey ring around the pot will be a rubber type of weather stripping or similar material so the pots will fit snug in place.

could use those gromets and silicon sealant,

Wow i just found an awesome video on youtube that pretty much answered my question

http://www.youtube.com/watch?v=7cPKDvo3jO0&feature=channel_page

I've used automotive dept. o rings to seal before. they work perfect and come in a million sizes. Thos tube setups are nice and i'm thinking about it now. good luck

instead of building a drain, do what i do, scrwe holes into end cape and let water flow back into rez

A grommet will do the job if it and the hole you drill are properly sized.
Get the T shaped ones:

It should tell you the drill size right on it.
For the 3" net cups, you should use a 2 7/8" holesaw.

Have you considered aero rather than NFT? It's not a whole lot more work. You could also convert later, I suppose.

Well, after doing alot of youtubing, i decided to buy a couple "vinyl posts" from home depot which is basicly a sqaure pvc pipe which will make installing alot easier. I'm going to buy a 2 3/4' (2 7/8'' if i can find it or maybe a 3'' if it will fit) drill adapter for the hole and use with 3'' inch pots which should fit snuggly without any sort of lining around the hole. I also found things called Bulkheads, which are used in plumbing and aquarium stuff.. Im going to call around and see if any places have them.

Once i get all this together and start growing with the flood and drain system, i might consider creating a fogger as described in this very helpful video i found http://www.youtube.com/watch?v=brvJ2fGXusU&feature=related but without the multiple hose adapter, ill figure out something for that.. maybe a very small pump just for the fogger.

For anyone whos intrested ive included another drawing of how i want this to turn out using the 4" inch vinyl posts as opposed to the round PVC.

nice. square will make a huge diff in ease.

finished setup design (miniture of course)