Geoffrey McGivern very welcome back (though I do like David Dixon's Ford), as is Simon Jones. Peter of that ilk is, sadly, indisposed, but John Lloyd would do a marvellous job. Better than William Franklyn, and definitely better than Patrick Moore.
Sad that Stephen Moore, the definitive Marvin, appears to be retired (though webby-science informs me he is rather older than I had thought).
Not too keen on Sandra Dickinson as Trillian, having been the most annoying thing about the TV series (aside from Zaphod's overpaid head).