Hire a professional and rely on her to get it done!
Get the girls to do the dirty work or if your parents are paying, they're more likely to have an investment to protect and can contact vendors to negotiate on your behalf
This should he number ONE because it truly is the best plan.
Listen, intently to your vendors.
Each one of them have a "business practice" or policy in place that makes them different from other vendors. Your request or plan should, therefore, also be unique. There is no simple answer for option three, except really try to understand what your vendor needs from you to serve you best. Once you know that, express what concerns and limitations you have. The vendor will appreciate your honestly and will be more willing to discuss options and perhaps even discounts.