I've worked for the government on small jobs here in the EU a couple of times, as long as you stay below a certain amount you can bypass a ton of requirements. But once you go above that threshold the number of players drops very rapidly and there is no escaping the formal process.

If you are capable of selling large contracts to the US Federal Government without having to submit a typical bid proposal then you are in a very fortunate position, but the people that I know that have done this in the past have all worked on stuff that either required their fairly unique skills or they were working on extremely small contracts (< $250K).