Well, the game looks pretty good even with potato runable tier 5 graphics and very good with tier 6 (unless zooming in on anything but weapons) which still doesn't need that much horsepower by today's standards so I'd just say get a decent pc which of course means you can play all sorts of other pc games as well.
And ofc nowadays this includes the majority of console games as well.

Buying a vita for this game is just absurd and from what I heard the vita version was never as good as the pc version in the first place.

We don't know what happens when the game gets released in the West, we all pray Microsoft won't demand ip block but there is no definite info on it yet.

Though, if you were ready to spend 250$+ I'd say spend like 5$ or so to get a couple extra mags on your main cause being able to play all classes on your main is a lot more convenient than spreading classes on different characters, which also usually prevents you from using some new meta builds.

E.g. most people got their GuHu character with maybe also Br and Ra for those builds but never lvled fi and then the lvl 85 gu skills make GFi really strong and anyone spreading fi and Gu on different characters (usually to avoid buying a new mag) either can't use GuFi or had to quickly try to lvl fi on their gu to 85 as well, which of course is quite an effort when you got another lvl 85 fi already.