I am a big fan of the Osaka Hilton. The rooms are good sized, clean (it's Japan!) and well appointed. It's my default hotel in Osaka from a price/value perspective. The OP is very lucky with the flight times. 10am means he may arrive in Osaka ~12 (after immigration + transit) which may be ok for checkin. And 5pm is perfect for not having to rush in the morning. And yes OP, go to Kyoto. The only problem is that you will probably want to stay a few more days to see everything that you cannot see in one day.