Can I get the kit with or without a transformer, resistor or speaker?

The only parts that can be added, removed or changed are the cabinet, tubes, and speakers. You can select variations to the kit from the kit detail page represented on the right of the item detail page under "Select Options or Variations...". If you change any other parts, it is no longer considered a kit, at which point you should just make a list of the parts you need and order them.