Hi Dave.
As I recall, the 4SE and 5SE use the same tripod, the 6SE and 8SE is SLIGHTLY different. The tripod that comes with the 8" is perfectly OK.
I met you at the last club meeting. My suggestion remains the same. Learn the ropes with the 4" and when you are ready, skip the 6" and go straight to the 8". If you buy the 6" you will shortly thereafter long for the 8", so don't do that to yourself. And if you REALLY want to treat yourself, consider the Evolution 8". More money but not needing external power is to me, life changing!!! You'll also want to get a lens shade (dew) and perhaps an upgraded finderscope.
Just my 2 cents.