“If” I was buying parts for an EASA-type, EU registered aircraft from the USA, then I would think about
• Buying from someone with FAA PMA approval. (Airtexinteriors are PMA approved, the suppliers TerryP has given in his post are not.) PMA parts are accepted by EASA without an STC if they are not “critical” parts.
• Making sure the part numbers are the same as the Cessna ones (this is important because you can only fit something with the part number shown in the Cessna Parts Catalogue).
• Getting 8130’s for everything
• Getting burn certificates.
And before I parted with my cash, I would check the engineer who is going to sign off the work and the company who looks after the ARC that the parts are going to be acceptable to them.
The instrument panel is a problem. In FAA land, this is easily (level of easy depends on FSDO and the Inspectors therein) dealt with under a field approval for which EASA does not have an equivalent. The EASA Minor Change will not get you approval of a new FAA STC and EASA will almost certainly think this is worthy of an STC rather than a Minor Change.