Hi also have a google on split ring mounts. I am doing one for my 18". These can be quiet portable and easy to mod a dob to suit and if done properly will not add a lot of overall hight to the scope and can be adjustable for a range of latitudes. They are in a way similar to a platform and many profesional observatories use this type.eg (Anglo Australian siding springs)
Stellar cat drives will function very well with this type of mount.
Mark
