A couple things to consider...
It's very easy to buy "up" in wireless router capabilities even when end "typical" end devices can't take advantage of (ex: MIMO).
I recently purchased the ASUS RT-AC68U and have been very happy with it. USB 3.0 port is on the back - I currently have a small SSD hanging off it, which I can access from anywhere through ASUS's mobile app or via the web. One of the purposes was to backup iPhones and photos there, reducing the need for an upgraded iCloud account, but I've been a bit lazy getting that set up.
If you go the ASUS route, I strongly recommend updating the router with the Merlin 3rd party firmware (it's actually built/layered on-top of ASUS's firmware - different approach than DDWRT, Tomato and others).
https://asuswrt.lostrealm.ca/One "downside" of the 68U... it sits "Up" which may not be visually appealing. If you purchase the rt-ac68u, check out the "white" model (68W). It typically is a few ($10-$15) cheaper than the black model.
DLINK's 880-L and Netgear 7000 are comparable. The Linksys WRT1900ACS is another interesting option... especially if you like the old style format.
If you're not in an immediate hurry, I'd look at camelcamelcamel, and set up a notification when the router of your choice hit's your desired price point. All of the ones listed above have dropped down considerably over the last 6 months.
Hope that helps!