Choosing a PK50

Hi, all.

My first post, here.

It’s 20+ years since I had a PK125(135), and I’m thinking about buying a project scooter, to rebuild.

In the UK, I can ride a 50cc scooter, using my existing driving licence. I may decide to take my Full bike licence, but one step at a time.

I’d welcome your advice around which model of 50 I should buy. For example, battery or no battery, premix or autolube?

What I do want to do:

Fit a Vape ignition (for consistent starting).
I’d also like to be able to use a USB charging socket (for navigation, etc.)
Potentially I’d upgrade the Speedo to a modern MPH version, which has other functionality, as found in the newer SIP-type versions.
Finally, I’d consider fitting a DR kit for a little more performance, without attracting attention.

Also, I understand that before January '89, the emissions aren’t so much of an issue.

Should I look for any PK, or would I be better off looking for a specific variant or model year?

Any help would be really welcomed, from forum users/ SIP staff.