Beginner questions for starting an NFT setup

Hello all, my brother and I are interested in starting a setup that will use NFT. We have never had an aquaponics gig before and are very excited to see how it would work. I will lay out the plan and please criticize/offer advice wherever you see fit.

We plan on using a 40 gallon tank and will likely start with goldfish and probably throw a few other fish in there to keep everything balanced (read plecostomus). We would like to build a spiral PVC frame for the plants to grow in, using a pump (of unknown volume) to take the water to the top where it will drip back down into the tank at the end of the tube.

Our biggest questions are

• what volume pump should we use?
• how long and what diameter should the PVC tube be?
• how many plants should we expect to support from a 40 gallon tank assuming 1 fish/gallon?

Please feel free to offer any advice that you might have!

I will update with any questions that I think of as I think of them.

Thank you!