Your first option for watching Star Wars should always be Disney+ But if you don't have Disney+ you can buy the movies on Apple TV. But if you just want to watch Star Wars, you should just get Disney+ for one month and then cancel the subscription. If you buy all the movies seperately, it will cost alot more. One month of Disney+ is 6.99 Euro.
Disney™ and Lucasfilm have always been friends in the filmmaking business. Disney bought Lucasfilm in 2012 for 4.05 Billion. So far they have made 5 Star Wars movies since they have bought it. Disney™ has made Disney+ since then and has made alot of money from it.
Honestly it comes down to personal opinion but in my opinion I prefer The Clone Wars beacause there is better constructed story, more episodes and is just more entertaining. Rebels is really entertaining too but there are less episodes and I don't really like the art style or story. But if you want a show to watch in a week or so you should choose Rebels because Rebels only has 4 seasons and The Clone Wars has 7.