You mentioned that this may be your last one, and you have others to use, so let's get this one perfect! Take your time to get the components you really want. A still hunting rifle should have the same fine characteristics as a grouse gun.
The choice of action is up to you. I've tried the lever and pump gun routes, but always came back to my beloved bolt actions when it really mattered. Pick the action that you like the best and find a used one if new models are no longer made.
I would suggest the lightest caliber you feel comfortable with so that follow up shots can be made quickly. Recoil has a way of slowing down re-alignment onto the target and you are talking deer - relatively easy to dispatch.
18" barrels seem too short to me. The muzzle blast is severe and balance never seems to be right. 20" barrels seem to give the best compromise in "shortness" while maintaining some balance. A factory tube could be easily shortened to whatever length you like best.
Now, the good part! Forget the cookie cutter stocks! Have a wood stock made up to FIT YOU and the style of shooting you anticipate. Remember the comparison to the grouse gun? I've never seen a Remchester bolt action with stock lines like an AYA double 16 gauge <img src="/ubbthreads/images/graemlins/tongue.gif" alt="" />! Have your stock made up with a more open grip and have the entire rifle balanced.
My perfect still hunting rifle would probably be a Mexican Mauser action with a #3 countour barrel 20" long chambered for either the 6.5x57 or 7x57 sitting in a French Walnut stock. (Hmm.... Maybe I should build one!)
One thing about weight. I do most of my deer hunting by still hunting. Usually heading out at first light and returning in the dark. I've carried all types of rifles and came to one conclusion: At the end of the day my arms are tired whether I carried a 9 pound rifle or a 6 pound rifle! What matters to me the most is how the gun mounts and balances.
Good luck in your search and enjoy the hunt!
John
