Do you have an iPad now? or Iphone? How much storage are you using right now?
It seems to me that 64gb is fine. I use it for the same on my iPad Air 2 (which I will upgrade with this new one) and out of 64gb i have 25gb free. Never really had an issue with space. My iPhone SE2 is 128GB and 60GB is free so it wouldn't work with 64gb but that is mainly because I don't organise pictures, videos etc. much. If I did I guess it could be ok but because I store everything on the iPhone and not everything on the iPad so its totally ok.
To give you better answer you should be a little more specific but from what you've said so far, 64gb is fine.
I wouldn't listen to the argument like "for this amount of $ you get x amount of storage" as that argument is irrelevant. Upselling is not a solution here. You always want to get a device that fits your needs for the planned usage. Just becuase something is cheap in general doesn't mean its the right choice. In fact, if you apply that upselling mentality and I don't then my 5th iPad will be free whilst you will have to pay for it. So you can think of it this way : )
So please provide more info if you want better answer or go for the 64gb. IN few years time you will upgrade it and by then the base model will be again different so you will have natural progression.
Let us know : )
Which version you recommend?
I will use it for movies, Netflix, internet browsing, some games, watching photos in Photos app and Apple TV +