Answers to both questions:
Exclusive Territory - that used to be the norm but in the last 3 years exclusive "protected" territory has faded away due to market conditions. Most companies/reps want a "territory" and that is either based on geography or vertical market. What works best is that you protect them on the accounts they sell and incentivize them with perks or spiffs for new accounts.
Commission Guarantees - most will not pay this because then it is like a salary and go against the independent contractor relationship and commissions. What you may be able to do is ask for perks or "spiffs" for new account openings, sales benchmarks met etc. I have a number of manufacturers that offer us a one-time cash spiff for every new account we open and that helps offset the ever-rising cost of road expenses.