I assume you're asking for the Alexa stuff so here goes.
The image and installation instructions are on Tuicemen's site:
http://forums.tuicemen.net/index.php?topic=1332.0You can order the X10 CM19A transmitter and an X10 transceiver (RR501 or PAT03) directly from X10.com or Amazon.
https://amzn.to/2ESImKh and
https://amzn.to/2VCRWXa or
https://amzn.to/2XDNLMNIf you live near a MicroCenter store you can get the Raspberry Pi Zero W for just $5 otherwise I recommend buying this kit on amazon for $27 that includes the PiZW, a case, power supply and a USB adapter (OTG) plus a few other items you won't need for this project.
https://amzn.to/2ESLGFqThe only other thing you'll need a 4GB or larger micro SD card. Bigger isn't better as backups will take longer. It's hard to find 4GB cards anymore so here's a link to an 8GB 3 pack with a card reader (you'll want the extras for backups):
https://amzn.to/2TxaKJZOnce you have everything in hand, if you follow the installation instructions step-by-step, you'll be up and running in under an hour.
In addition to using Alexa to control individual X10 devices you can use it to trigger macros in your Plato using an otherwise unused X10 address.
Regarding my comment about using Teamviewer to remotely access the laptop connected to your Plato, you can install the free version of Teamviewer on both PC's from teamviewer.com and follow the setup instructions.
Regarding the potential failure of the Plato, it might pay to monitor ebay or any Plato user groups to try and buy a spare unit. I have two spare Stargates that I've picked up over the years from ebay that I bought for a song.