If you have really steep hills, a 32 tooth rear sprocket is useful. Mine are 15% so I need that. Otherwise a 28 tooth biggest rear sprocket is fine. When a rear hub motor addition forced me from pedal bike 8 speeds to 7, I could never find a 7 speed freewheel in stock with a 32 big one. Was in the catalog, available only overseas I suppose.
Hydraulic brakes are IMHO for bragging. When you change pads and push the pistons in, they might leak, which means you need a new caliper. Cars certainly frequently do that. Read maintenance forum about hydraulic disk maintenance. Pads last 4000 miles or more.
My cable pull tektro disk brakes are fine, even down the 15% grade. I adjust the pad in about twice a year to keep handle position the same. It takes longer to take the pannier (bag) off to reach the back adjustment than it does to turn the adjuster. I turn the bike upside down to do this.
For ultimate smoothness you can change the cable to stainless steel polymer coated, which costs about $15. I did when I broke the front cable after 15 months. Special parts are available from modernbike.com and thebikeshopstore.com
$500 extra is worth it for a suspension if you're going fast. 10 mph, fixed suspension is okay on 2" tires. But you didn't say anything about a suspension being available.