Subtle yet effective? Help me, I'm a noob.

So I've just bought a Schwinn Stingray and want to put an electric motor on it.
Don't want anything super powerful, just hoping for something that can have me cruising at around 40km/h, with a range of about 50+ kms.
I was really trying to do it all myself, but after looking at what seems like about 50 different kits available online I've got myself in an absolute fluster!
I want a kit that's fairly sleek in design because I don't want to ruin the cool look of the bike.

I don't know a single person who has used bicycle motors, especially not electric ones, so I don't even know what brands are trustworthy or anything.

What do people suggest??

One that has caught my eye:
https://electrictransportaustralia.com.au/index.php/Index/product/ca_id/2

I live in a bit of a valley, so its one bit of a hill to get out, but then its pretty much flat..

And front hub was definitely my intention. After talking more to one of the guys from the link I posted, he has given me a bit more insight into the motors and he thinks it would install onto the Stingray with no problems whatsoever..