Sharp PC-1250A and CE-123P.
The PC-1250A is probably the (physically) smallest computer in my collection at the time of writing. It is considerably shorter than the PC-1403, and has similar capabilities; however, it lacks a dedicated calculator mode and calculator keys. The math functions in it are quite full-functioned; you just need to do rather more typing than is necessary on the PC-1403.
The CE-123P combination thermal printer/cassette interface is probably one of the best printers for the pocket Sharp computers; it uses standard 2.25"-wide thermal paper, and the print head is reasonably durable. The head is, however, a semi-consumable item.
Oddly enough, Philcap Electronics (http://www.philcap.com/) has, at the time of writing, small stocks of spare mechanisms for this printer (or more likely some cash register or POS terminal that used the same mech), including the print head. If you happen to be in the Akron area, it's worth dropping by to pick up a few of these mechs.
There exist a couple of emulators that claim to be able to emulate the PC-1250A but I have had operational problems with both of them. I'm still investigating this.