Full disclosure, I've never used the NFL+ service. Per the web site, they have different tiers - the Premium is their top tier and is what you need to get live games. It definitely only works on tablet/mobile devices - that's because of exclusivity with "NFL Sunday Ticket" on Youtube - you can't even 'cast' your mobile device to a smart TV to watch NFL games (it will give you an error message if you try). Some folks on Reddit have discussed ways around that block, but it's not for the faint of heart (technilogically speaking)...

Hulu is 82.99 per month, correct.

Far as which tablet, the only advice I can give you is "don't skimp". But that said, you also don't need to spend $thousands for the absolute latest IPad Pro whatever they are now. I'd suggest doing some Internet research to find out what people are using for streaming.

One other thing I just thought of: I'm not sure whether the NFL + Premium will require you to have a tablet with cell phone service, or whether it would work through wi-fi only. You'd have to research that further as well. It says it's for "tablet/mobile devices", but it doesn't say whether it needs to be cellular enabled. Point being: check into whether the setup you're thinking of will work how you want it to before you spend a bunch of money and find out otherwise...