Hey Chris, welcome!
I think the plan is that a number of Abarth service centres will open around the country, so oil changes shouldn't be a problem.
As far as I know, the standard Abarth wheels will still fit after the Esseesse kit has been fitted, so if that's what you'd prefer, I can't see a problem with it. ChunkyMonkey, our resident tech, will be able to confirm.
I suspect that the Top Gear piece was filmed some time ago. But, even bearing that in mind, we
still don't have confirmed prices for either the standard car or the kit.
Stick around!