Recommendations for 24V to 5V AC/DC converter
1) No. Those converters will not work on 24 VAC.

2) This is not a site which permits product recommendation.

3) If you don't mind some extra size and weight, you can get what are called bell transformers (used in doorbells, naturally) which take 120 VAC in and put 24 VAC out. If you take one of these and feed your 24 VAC into the secondary, you'll get 120 VAC on the  primary, and you can use this to feed your converter.

5 volts time .5 amps is 2.5 watts. Ignoring converter losses, this implies that 24 Volts will only need 0.1 amps, and this is a very small transformer.