First two may be very difficult to find locally as these are considered the best SE variants, the POC probably being the best (definitely my best so far). The last two may be easier though don't take my word for it.

Best bet is to buy online, definitely can find but may cost a bit more than their RRP. All the best hunting them. Get a couple extra of the POC SE, worth having him displayed with all his gears and the two head variants