Are you wanting an oldschool full guide, or just a top one? If you’re thinking top only, then really it makes little sense to do that with a standard ring- it’ll be pretty much as expensive, more hassle, and less reliable than a top guide.
This is the best value chain retention there is, imo:
http://www.superstarcomponents.com/en/i-o-chainring-narrow-wide-style.htm
It’ll hold the chain better than any top guide I’ve used. And in the event the chain does fall off, it goes back on easily! No jamming.
I wouldn’t recommend the Superstar top only guides, the backplate of the XCR is a bit bendy, it does work but it’s not brilliant. An MRP 1X is a fair bit more expensive admittedly but it’s also a lot better.