Ducky thick PBT sets are probably the closest to the Poker caps (thick OEM profile PBT):
http://zealpc.net/products/ducky-pbt-keycapsI think the OEM profile ones sold by Feng are Keycool and if so they're only medium thickness, thicker than most stock ABS caps, but thinner than stock Poker II caps and "thick" Cherry profile ones.
If you don't mind Cherry profile (I actually much prefer it), then there are a whole lot more options. The actual typing feel is fairly similar, but they're lower overall profile.