I have also been a kegger for many years now and thought I had left bottles behind. But I found myself in the same place as you are now. For special beers that you would like to age, bottles become the real option again.
I use a Colonna Capper/Corker. It is about a $80 investment but becomes your go to capper and corker. It has an adjustable depth so it works well for Belgian bottles.
Make sure you use the cage on the Belgian bottles after corking. If not the corks will likely punch out if the pressure builds up during the bottle conditioning.
Since you are cellaring, make some nice labels with a laser printer and stick them on with skim milk. You'll find over time you forget or lose the specifics of the batch, what it is, when it was brewed, and ABV.