What a tough decision for a young pilot to make!
1) Keep racking up those valuable SE piston F/O hours on the GA8 Airvan, or
2) Step up to the plate an try for "Command" on the mightly C182RG.
which position should I take?
Something different to the one you are currently in! ....... errrrr, that's the one where your draws are down around your feet and your hands are tightly gripping your ankles.
Rat 
PS: I had 150 hrs TOTAL when I made "Captain" on a C210 - but I guess I was something of a progidy!