I emailed PBP support re this matter a few weeks ago and they replied that they though code compilied for another pic would run on it. I will post details later I don't have access to it here. I think the issues were that the suggested pic has more ports, so as long as you didn't try to use them then hex code for the substitute pic may/should work on the 12F1840.

I also spoke to piccircuit .com who make a neat cheap pickit 2 clone and they sent me a file to allow the pickit 2 software to work with the new device.

I'll post details later.