I run a full node on my Raspberry Pi at home. I want a desktop wallet that uses this full node. Not interested in using remote-x or xpra or setting up an electrum server.
This mostly depends on the use case.
You can either
1) use core on your desktop PC and connect to your node (either exclusively / or additionally).
You can use one of the following two commands:
-addnode=
to additionally connect to your node, or the following to exclusively connect to your node:
-connect=
This still requires your PC to have the whole blockchain saved.
2) directly connect your raspberry PI with your PC and change the data directory of your PC's wallet to the data dir of the full node on the raspberry pi.
This makes it not necessary to have the whole blockchain downloaded on your desktop PC.