Also: Buy a the longest code signing cert you can. Reputation is acquired at cert and build level; updates signed with same cert are cleared much much faster. Cert reputation is lost when it expires, meaning back to square one to sign updates.
I've never had a smooth ride getting a Code Signing Cert, always some stupid bureaucratic rubbish to deal with, or the need to run some stupid obsolete browser in order to actually get the thing, and I know at least 2 others who also ran into the same crap.