Hi Baytonemus,
The Report Designer is Windows-only for a few reasons. Firstly, to develop a version of RD for Mac would require an enitrely new program built from the ground up, which would require Significant development resource investment - its not quite as simple as flicking a switch.
This being said - certainly not ruling out future iterations of Report Designer including a Mac version. You wouldn't be the first person to request this!
Regarding having someone from the team design a report for you - This would entirely depend on the complexity and requirements of the Report. Check out the Consulting Services page for more info about costs involved.
Feel free to shoot me an email at Success@method.me and we can discuss requirements. I can then run it by the team to give you a more accurate estimate of time involved.
Thanks Baytonemus
-Ben