I love the DR-2d but I usually run 4ch. I know he's probably just starting with 2ch but I know there were times when I first started that a second source(like SBD) would have been nice to have had. The big advantage for the DR-2d is the 4ch function. I would also recommend the DR-05, mine usually gets about 14 hours on 2 AAs. I'd imagine the PCMM10 has a better DAC, but the DR-05 is very cheap in comparison. It all comes down to how much money they have to spend and how much each part of the rig matters to them.
As usual, strong recommendation for CA-14s or CA-11 mics for anyone running this type of gear. I'm sure some ATs would probably do the job as well. It's not absolutely essential but I would recommend a CA preamp with the CA mics(instead of a BB). The reason being that I typically have pretty low levels when running the CA mics > BB > mic in on these type of devices. I guess if we are running 24 bit it shouldn't matter much but I prefer the sound of the pre in most cases. Not pretending to know anything technical here, it just sounds better to me.
You might want to clarify to them that they need to cater their decision to how much open vs. stealth taping they are doing. That can be pretty important in deciding which recorder, which mics, which power, etc.