Hi
I'm not sure why you've put the PHP, but definitely following solutions may be provided to upload MV listings on Amazon UK account.
1. A desktop application can be provided in which you will be maintaining the MV listings with relationships. On clicking upload, your listings will get updated. For that, you will be required to authorize my amazon developer ID to your seller central for updating feed.
2. Can provide you application that can generate 2 XML files (as requested by you), to upload them in your seller central.
For sure, they will be uploaded to Consumer Electronics category!
Cheers mate,