Hi, I'm ready soon to place them into net pot...

Go to a hydroponics store and just get standard round ones. I find they are all for one use only as the roots get that big.

They are all made of plastic of varying sizes and shapes. There is no "Best One". There is what works best for your situation. You can use a 3.5 inch, a 6", a 12" whatever. Their all the same. Just pick one that will work for whatever setup you intend on using.

This item is basic moulded plastic and should not cost that much. Try visiting a hydroponic/grow shop in your town or the next they should have them for cheaper then that. Also the style of basket will depend how your growing them. if your using 5gal pails in a DWC or RDWC style grow the first one looks best. Or just cut a hole in the lid and set the net pot inside of it. Also they are not great unless your growing in a hydro style. My Hydro shop sell net pots for $ 1 . 50, lids for buckets $ 2 . 50, or the all in pot-lid for for $ 5 . 00, 27pounds to cad is 48, 48/4=12 a pop. Pretty pricey for plastic. Good Luck!

I believe any of them would work just fine so long as the roots can get through, and all of them seem good to go.