Calculating PSI CFM and capacity for moving falling object

by RedCap
(California)

First of all, congratulations on a most informative site !

I inherit a project that needs to move a falling object a certain distance with compressed air controlled by air valves. I am an electronic engineer and have no air flow background.
How do I calculate how much power, PSI I need for say 500gm objects falling from rest for 400mm before reaching the valve. The object must be moved for some 300mm out of it's falling path.
The objects is about 100mm x80mm in diameter.
The installed valves have a 2mm nozzle, and can move 300l/min air at 8 bar. I have a bank of ten valves next to each other, the nozzles are 10mm apart. Thus, 8 to 10 valves can be activated at the same time for moving a 100mm x80mm object.

The electronics can control the length of the activation time of the valves.
We would like to keep the valves but can change if that's what needs to be done.

Questions: 1. How do I calculate all the relevant air parameters. 2. Nozzle size, flow, psi, total cfm's. 3. Any available formulas you can point me to ? 4. Would I need to have a receptor/storage tank to manage a continuous flow of objects that can help
?
I think this can make out a nice, complete HOWTO once we solved all these issues.

Obviously we could go for the biggest airflow and pressure but would love to optimize air consumption and thus power / generator requirements.
I would appreciate your help or any one's that have this type of background and/or knowledge.
Thanx in advance.
REDCAP ca.