This makes me wince, glad @BLUEFROG caught it too! If you’re removing your Mac from your setup, you should as a minimum set up one device that has a full download of your files. It makes sense for that to be your iPad, so you need to buy one with enough GB to store all your databases.
In your first post you said you would be selling the Mac before you’d bought the iPad. Whilst I appreciate there will be logistics to this, if at all possible that is not the way to do this. If something goes wrong with your iPad set up you will be stuck with no way to rescue your databases. If possible, you should buy the iPad, do a full sync of your databases to iPad (not a shallow sync!), verify that everything is how you like it/expect it to be, and then consider wiping your Mac.