Get the sturdiest tripod you possibly can. It's is THE foundation of everything you'll do upstream. I tried and wasted a month trying to get a cheap tripod solid enough for astrophotography work. If you are handy, don't discount building your own foundation for the EQ Base.

Ball mount is useful if you get this and don't use the Dec bracket. You will lose counterweight though. I can't see why you would put a ball head mount on the dec bracket, just one more thing to cause issue. Good Luck!