Hi Oliver,
One of the few things EASA has brought us is easy to comprehend regulations. OK, maybe not, but some of the EASA regulations work well for some of us. In your case, it could work very well.
First of all, you need to understand the difference between CAMO and Maintenance.
EASA says that your aircraft must be managed i.e. a responsible person or organisation must manage the maintenance (including mandatory requirements e.g. AD's). You can do this if you are the sole owner, or you can contract this responsibility out to an approved CAMO (EASA Part M Subpart G).
EASA also says that your aircraft must be maintained.
These are two seperate issues.
If you purchase your 'G' registered PA 28, then enter into a contract with a UK based CAMO for the management of your maintenance, you can then have the maintenance carried out by an EASA licenced engineer or EASA approved maintenance organisation of your choosing (if you are operating the aircraft for private use).
The CAMO will create an approved maintenance programme for your aircraft, based on manufacturers information and regulatory requirements OF THE COUNTRY OF MANUFACTURE AND THE COUNTRY OF REGISTRATION. The CAMO will advise the maintenance organisation of what is required and raise all required scheduled maintenance. The engineer or maintenance organisation will carry out the engineering, and then return all paperwork to the CAMO. The CAMO will maintain records and if they are also EASA Part M Subpart I approved, issue your ARC (providing the engineer / maintenance organisation doesn't condem your aircraft).
Hope this helps. If you would like to know more, please feel free to PM me.
camlobe