Babysitting Help Needed - Flexible Hours!

Hi - my wife and I are hoping to find a few new babysitters - preferably those who will be in the area for the next 1-2 years or so, as we're hoping for someone to build rapport with our kids. You would be occasionally babysitting our two youngest (10-year-old daughter and 7-year-old son); no rigorous structure here - just playing games, making snacks and the occasional meal, and putting youngest to bed. We need help with everything from watching the kids when we're at afternoon appointments, weekends during the day, date nights, etc... - especially someone who would eventually be comfortable with staying for an overnight or two so we could do an occasional night/weekend away. Also, our daughter is autistic so someone with special needs experience is a bonus, but definitely not a requirement. Thanks so much in advance...