Your build seems pretty sensible to me, including the PSU

Tzoi:

 

Your build seems pretty sensible to me, including the PSU

 

Thanks.

currently struggling to find a z370 mobo around 220-270 by tomorrow as i want to get in on all the sales.

It looks like most mobo ive looked at had 2 or 3 fan headers and my case will use up to 4 fans. whats the best way of connecting the extra fan, a fan splitter?

You'd need a fan controller - some cases come with one, though looks like yours doesn't

Something like https://www.pbtech.co.nz/product/FANDPC1064/DEEPCOOL-Fan-Hub-PWM-4-Fans-4-Pin-ontrols-up-to-4