18 vs 19 inch for ebike rims and tyres?

I'm at that stage in my build where I need to choose the rims and tyres and can't decide whether to go for 19" or 18" rims. I was originally going to buy a set of rims and tyres that were 19" for the convenience, but I've looked around and found some good deals on 18" rims. I know Andy Kirby used 19" and Tony Vortecks used 18" and both work fine. I think I'm correct in saying that smaller wheels give slightly better acceleration but a lower top speed which as I'm after acceleration is a small benefit? I'm slightly drawing towards 18" as they give more clearance up front and I've found some suitable ones for good prices, but any thoughts on either size?

Totally depends on the geographic area you live in for the availability of tires. I would literally go to the store and see what they have in stock and also see what they have available in their catalog for order and delivery to their store on their next order.

Kimpex is a good site to browse but they have little in terms of moped tires. TreadlandTV is a good site also for moped tires and rims.

18 inch is a more convenient size. 19 is uncommon with lesser choice. The hard part is to find them light weight, rims and tires. Those are not likely to be found cheap. A quality lightweight alloy trial rim is 200$ normally.

Smaller diameter on a hubmotor provides more acceleration, better climbing, greater efficiency (cooler motor and greater range), and not necessarily a lower top speed due to running cooler, at higher efficiency and a lower ride height. That means if you can make a 17" work for you it would be even better.

Sounds like 18" is the better option for the better acceleration and wider availability. Thanks