Jameco lists several supplies that might work if all you need is +5
and +24. Stock no. 194897 shows +5 at 3.5A and +24 at 2A for about
$33.
Jameco also has an interactive on-line product selector.
Anotehr alternative is to scavenge an old linear PSU from an 8"
floppy box. These supply +5 and +24 at pretty hefty currents.
--Chuck