This makes me think of some of the posts where guys are asking to design stuff and the sky is limit when it comes to money. It is ridiculous too think like that, and while we need to show some restraint and practicality for money, this is good opportunity to try this.
Why are we just rhyming off the equipment like the answer already exists, like some civilian engineer/industry salesman has already figured out our solutions? Perhaps go back to when the military were the engineers, and we decided what was going to be created. Thinking of the solution without analyzing the problem will get you the wrong answer more than not.
Does it need to be a tank? I think not. Perhaps it's several things in a system, instead of a hunk of steel with a gun attached to it.
First off, what are the airborne troops deficient of ie. what do they need that they don't already have? You can't answer tanks either. Is it Lethality? Mobility? Protection? Comms?
Lethality, may be not so much, there are plenty of hand held weapons that produce massive effects. Not to mention the higher level support that these troops will likely have.
Mobility, yes they are somewhat deficient, but paratroopers can cover ground pretty good, and if there main task is capture, hold and upgrade ground, then mobility may not be a priority.
Protection, yes this is big one, and what they are likely missing the most. Does that mean they need a tank? No, because you can only fit so many guys in a tank, especially a small/light one that can be dropped. What are the other options? Fortifications, obstacles, active defenses? There are all kinds of options that don't involve 20 tonnes of steel. BTW if part of the answer is a vehicle, then steel will likely only be the structural shell. Costly, special materails will be needed to be added, such as ceramics, plastics, glass, active armour etc.
Comms is another nut to crack. How much information needs to pass back and forth? There is quite the divide between frontline troops and higher command when it comes to answering this one. Front troops, just want theirs orders and then get on with it. They also want the capability to ask for additional support when required. Higher HQs are sometimes the other end of the spectrum, wanting and giving constant feedback. I think our needs can be met already, as long as the back and forth info is prioritized, managed, and kept to what is actually necessary.