The current release, 4.2, is here
If you're having trouble with the market, use the aCCleaner included on the new firmware to wipe all the app data, then reboot.
You can sideload any apk file you can find. You just need to load it on an SD card or in the root of the device. Use the APK installer to browse to the file and install it.
Let me know if you have any more questions. Glad people are having a look at the project.