Okay, there were a few comments on both Amistore and IndieGo! Appstore blog entries that may clear up some issues I had at the time (I plan to revisit each when they are out of beta).
Two solutions were suggested:
1) Change the default URL handler in the system prefs to use another browser, such as OWB
For IndieGo! I had a few concerns and the author of the program left suggestions for each:
1) When selecting the platform, I could only scroll using the arrow keys. Apparently, if the mouse pointer is over the list, the wheel should work. He said selecting more than a single platform selection will be supported in the future.
2) The download speed after purchasing an item was unbelievably slow. This turned out to be a buffer size setting that he said was easy to fix:
Open with a thext editor the file
Edit the line nr. 10:
And replace the 64(Kb) of buffer with a higher value like 128 or 256 to speedup the download
Full re-review when final versions come out.