40a is a good balance for the future even though SE will max out around 32a. NEMA 14-50 will allow you to swap it out if it dies or take it with you when you move. Hardwired would allow outdoor install or bypassing the need for a GFCI breaker. Other than that consider where to install it. With a multi car garage for example, could you install closer to the middle should you get a second EV and want to share? Cheaper to do it once rather than throwing it all away to move it to the right spot.
As far as unit, get an EVSE that is well reviewed and UL listed, not the cheapest thing you find on Amazon. EVs and homes are expensive, would be a shame to destroy either with some sketchy equipment. I went with an EA HomeStation. It's integrated into the main EA app, but not a good value and way bigger than it needs to be, wouldn't buy again. Grizzl-e makes some good stuff and that's probably what I would get if I were shopping today.