Hello and Welcome.
So sorry to hear about Jonno.
We home seniors. We got Potion at 9 years old and it was not evident to us how much she wanted another fur friend until we got Melody. We always have two now. I believe it really helps the older one. Right now we have Mardi, now 11, and Archie (GSD) who is 6. I've been doing this for many years now. I would not have gotten Archie, being so much more active than Mardi, if it had not been for his circumstances. We could not turn our back on him, his circumstances and his needs.
Seven is a good age, past the puppy antics and sounds like it would be good for Jonno. Of course, it's Jonno's choice if it is a good match.
Looking forward to pictures of Jonno.