Unfortunately, there don't seem to be a lot of pigment-capable small printers out there. The R1900/R2000 and 1400/1430 are all about the same size as the 2880. Your best bet might be to find a used R800, which is the letter-size version of the R1800. Same cartridges, same print head, etc. It has the 1.5 pl drops that the R1800/R1900/R2000 do.
It is only a single-shade black inkset (but in PK and MK without swapping, AFAIK.) Combined with a 3rd-party multiple-shade pigment black ink set, it would probably make a great 8x10 printer. It's driver doesn't support ABW mode like the 2880, so you'd have to use QTR.
--Greg