MEbound
Although I understand that you're thinking about the future command I will recommend you and all other F/O:s to also look at what kind of life you have until you get your command.
If you just focus on the target you will not enjoy the years you spend reaching it.
Which airline offers you the best life as an F/O? If the difference in Captain and F/O pay is small and the working conditions at the flight deck is good then you shouldn't be too worried about a couple of years extra as F/O.
I enjoy being Captain but I also had a lot of fun during my almost 15 years as a F/O.
Your flying career will hopefully be long, enjoy all parts of it!