Scrum Implementation Case. Looking for Scrum Community Advice

As I got more and more familiar (on theory level) with Scrum I’ve started to think about the implementation of it in my company and I would like to hear your thoughts on my case and answer my questions for me to properly address it to management.

Pre-requisites:

1. IT Solutions:
   1. Oracle Hyperion Financial Management (Financial Consolidation)
   2. Oracle Hyperion Planning (subsystem «Management Reporting» with Commercial (B2B/B2C), Technology and Finance analytics, subsystem «Rolling Forecast», subsystem «Human Capital Management»)
   3. Dashboards solution
2. Key Stakeholders / Departments (located in the Netherlands):
   1. Tax Department (1.)
   2. Consolidation Team (1.a.)
   3. External Reporting Team (1.a.)
   4. Management Reporting Team (1.b. subsystem «Rolling Forecast» + 1.c.)
   5. Planning & Forecasting Team (1.b. subsystem «Management Reporting» + 1.c.)
   6. HR Team (1.b. subsystem «Human Capital Management» + 1.c.)
3. In-House Proxy – EPM Department (consist of me and Director)
4. Outsourced Developers:
   1. Oracle Developer (5-15 FTE, depending on Release, including Tech Lead and Change Manager from their side for Client communication) – Located in Russia
   2. Dashboards Developer (1 HC, not full-time) – Located in the Netherlands
   3. Administrators Team (2 HC) – Located in Russia
5. Current Approach:
   1. Quarterly Releases (had to change to quarterly due to the poor quality of monthly)
   2. Waterfall Approach
6. Additional Constraints:
   1. SOX-compliance
   2. No auto-testing capabilities
   3. No automatic regression testing

My first thought on how it can look like (at least at the earlier stage):

1. Product Owner: Me (as more or less I’m already doing most of the core activities of PO)
2. Scrum Master: prefer independent but taking into account budget constraints – from Oracle developer side (current Change Manager can be considered with prior preparation or someone new can be taken)
3. Development Team:
   1. Dashboard Developer (1)
   2. Oracle Developer (2-6)
   3. Stakeholder department specialists from impacted by specific Sprint area (management reporting, forecasting, etc)
4. 4-week sprints (would like to avoid often releases for now)

My concerns (can this even work):

1. 1st Sprint and already geographical distribution of Scrum Team
2. Involvement of business specialists on a regular basis as a member of Scrum Team
3. Accordioning of Scrum Team depending on Spring (Dashboard developer is paid on an hourly basis and involved on ad-hoc + nobody will allow 100% membership for a specialist from the department if there are no changes in the respective module of IT landscape)
4. Product Owner = Client Representative
5. How to consider SOX compliance UAT approval requirement in DoD if it should be better Sprint Review before UAT will be formally approved?

Thank you in advance for your thoughts and answer about my concerns on this case