On the model, you show BOTH ends of the ball screws using BK bearings which are the fixed end bearings, which is the best way to fasten, BUT it's not the standard way. Usually, you have a fixed end BK bearing and a floating end BF bearing, so if you want BK on both ends you will need to tell Fred at BST otherwise they will machine them to standard.

Also mention you want the "F" Dimension which is the coupler portion at 25mm otherwise they will machine it 15mm.

Tell Fred you want the best BK/BF bearings not the cheap ones.