Yup installation manually is the right path. IOS60 v6174 and system menu 4.1 for your region works fine. I wouldn't even worry about the ios's update them when it is necessary. sometimes older ios are better than newer ones (trucha bug already enabled). I've done this multiple times, and it sounds scary, but there is actually little risk.
if you go into HBC load wad manager, install IOS 60 FIRST then system menu, exit the program it takes you back into HBC. From there install Priilloader BEFORE exiting to system menu, just in case. then you can access priiloader, even if you have a corrupted wad or something silly like that.