Absolutely Janet, go for the Staging!! Staged homes always win over vacant homes, in my opinion. As for the house sitter, do you mean someone to pretend they live in the house while potential buyers come through? If so, you can skip that. But if by house sitter you mean someone to come along before showings and touch up (dusting, cleaning up the yard, flush the toilets, etc...) then by all means, yes! The ideal situation would be a vacant (no one living there), but beautifully staged, home.
As for staging, you can get great rental furniture and accessories and a Stager will be able to help you in coordinating this. Staging will concentrate a potential buyer's focus on the home's most important features, or those areas you wish you emphasize. Staging will also help potential buyer's to visualize themselves living in the home. Using neutral color palettes and eye catching artwork and accessories, a Stager will be able to create flow and help form a great first impression!
After staging, professional photography should also be used in all marketing as well, being sure to show the entire house in its true form. If you staged your home, yet have photos of a vacant home in your marketing, buyers will be misinformed and show up confused.
Best of luck to you and feel free to contact me for additional information on staging your home for sale!