It seems to me that the size of the van you require depends on what kind of furniture you plan to transport and whether you intend to disassemble it, so that it takes up less space in the trunk of the van. However, I don't think that renting a van will be cheaper than hiring professionals for this. For example, on this site https://allinmovingsystems.com/ you can get not only professional help with your move, but also you can get a quota for their services and save your money. I advise you to turn to them and then think about what will be more profitable for you. Thanks to the discount on their work, I realized that it's more convenient for me to use the service provided by such a company than to worry and spoil my mood in the hustle and bustle of the move.