That's right. There's no way you can tell you have an A1026 or A1027 unless you take it out of your computer, sadly. Luckily, there's a plethora of PCMCIA network cards based on Atheros5k chipset that work 'out of the box' and you can get them much cheaper than compatible Apple card (I got one for about 4 EUR, shipping included).
Can you please link to one of these?
Henry Lerche Rasmussen