The biggest challenge you will face with Express is the limitation on the number of trays you will receive. 10 is the limit and it is only possible to move a tooth a certain distance with one tray. This is difficult to assess until the case has been submitted.
I never charge for records when the patient is commited to Invisalign so I take the impressions and submit the case to see if it is Express or Full. If the patient books for one or the other, no records fee will be assessed, but if they don't do any treatment, I charge $200 to cover time and materials. I bet you could find a provider to do that for you. If you don't mind the gamble of losing $200 to "see" if Invisalign Express is possible, you could try that, if you are committed to either one, then you wouldn't lose anything.
Sometimes a case will come back with 12 trays and I will tell them to modify the plan and get it down to 10. They can usually do that, especially if you are fine with an "almost perfect" result.