I don't think you'll have any problem finding what you want. There are lots of great swing keel designs in that size range, and many are already set up for single handed sailing. Small Craft Advisor small ads are one way to go. Found this straight away :
Small Craft Advisor - West Wight Potter 19
In answer to your question about equipment, it might cost about $2k to buy a roller furler for the jib, get the jib adapted to suit, bring all the reefing lines and main halyard back to the cockpit, and buy a tiller pilot. I had lazy jacks but took them off, did more harm than good.
But there are so many smaller boats out there set up for single handed, I don't think you'll have any trouble finding one.