It really depends on how much cash you are willing to put up, and how much testing you've already done. There are a series of tests that must be done prior to a rocket launch to ensure compatibility. These include fit checks, flight path analysis, vibration analysis, and others. If you were to be the primary load on a spacecraft, then you'd have to make sure all of these were done. If you paid extra cash to ensure that you were given priority, and bumped other payloads, then you might be able to accomplish the task in 6 months, especially if you were willing to be flown on an experimental flight, such as the Falcon 9, that happened to be aligned with your time table.
The most parallel example in recent years that I've seen to your situation was the launch of the Cygnus capsule on an Atlas 5. The failure of Cygnus was at the end of Oct 2014, the launch of Atlas 5 was Dec 2015. I suspect just figuring out which provider would launch required a month or two, making that time to launch at about a year. I doubt that they paid a premium to do this launch, although I would argue that any ULA launch comes at a premium.
Finally, note that with SpaceX in particular, the manifest has been in play for a long time. Several of the payloads launched had been waiting on the ground for extended periods of time, ready to launch. Some satellites also aren't completely ready. You might be able to slip in the cracks and have a launch sooner, if you are completely ready to go, or you might get bumped for some time. There is a lot of randomness to rocket launches still to this day.