There appears to be a bit of a shortage of APS and APP rated ATCOs so he or she could do either of these and do ADI later if so desired.
Indeed there is, however, APP without ADI is no use to anyone and there's no chance of employment with just APP.
The option of doing Basic and APS is indeed a very sensible option, however, for someone with no ATC experience at all, it's a huge risk.
If dB had was previously a very experienced Mil ATCO with all the ratings, there'd be a very good chance he'd get through the APS Course and be very employable.
Even with that experience, it's a very difficult course to undertake, as any ex Mil person will vouch for, without it, you'd be better off doing all from scratch.