A good ipad for a reasonable price is the ipad mini 6. I have been using it since its release date and I must say I haven’t had any issue with it. IF runs a Max graphics with no issues and with the A15 chip the ipad will last you quite a while with performance.
If you wish to look into other devices Device Compatibility Thread 22.3 - Built By Us For You! is a good thread to see what’s best for you.
You don’t have to buy a new subscription, logging in with with account details will be fine
Replays don’t move over with accounts as they aren’t on any database to my knowledge and only save on that specific device
I have just done this and have some good news for you:
You only need to pay for the base app of the game again on your apple device. Its either 99 cents or free from what I remember.
You do not have to “repay” for your sub. Assuming you will keep your android device you can just link IF on your phone to your forum account through settings, and then link IF on your iPad to the forum account and the sub will work on both devices. (You can not fly on both at the same time obviously…)
I unfortunately dont have any tips on the iPad you should get but my steps above should help you in the process.