No, a cheap GPU won't really help either way. If you're just doing non-intensive stuff on your other monitors then your 970 won't be taxed, if you are doing intensive stuff then a cheap GPU won't help.

I personally wouldn't get a monitor that big, but if you think that's ok for you then go for it. IMO both those monitors are expensive for what they are, but I'm kind of picky about monitors. If I were you (which I'm not) I'd look for some local dell ultrasharp panels to use as secondaries (IMO they are the best non-primary displays). Right now I'm using a single FP1355, so yeah, this kind of topic is mainly personal opinion - unless you want to optimize a specific characteristic or set of characteristics.

I'd like my main gaming monitor to be 1080p+ 144fps with 1ms delay that has pretty good pixel density as well. My only criteria for the 2 other monitors is that they be similar looking to the gaming monitor and the same size. If they were different I'd lose my bloody mind.

Faint, that'd be lovely of you

Should be a decent choice then I think.

I was thinking more of a PLP setup.

"It's ok to have more than one monitor but if you're doing so you'll want to have multiple graphics cards and good cooling"

Is this good advice?

Are you playing games across more than one monitor?