Build a few sockets into your body, in strategic locations, for simple plug and play body parts. Reroute two or three motor nerves to each one, and add a rechargeable battery. Should be doable with today's technology (like electronic prostheses really). With 2 nerves you could already control 2 movements:
open and close, which is good enough for most stuff. Or 4 for movements (for the non-gripping parts): up down left right.
The real advantage of the PnP body parts would be their specialised nature: you would change them to suit the job at hand, unlike your current body parts that have to cope with hundreds of different tasks.
The professional versions would have a "stainless steel" look, while those for private use could be in a more natural style. The styling solutions are of course endless.
One (a small one) should be near your wrist, for an extra finger-like thing, for precision manipulation. You could plug in a pair of tweezer-like things there (watchmakers), or a screwdriver (whoever), or a bottle-opener (bartenders).
A bigger one could be near your hips (close to the centre of gravity) for heavy-duty lifting and carrying. Plug in an extra gripping tool to carry grocery bags (or hold the hand of your third kid). An arm with a suction cup to help you balance any heavy stuff you're carrying.
One would be somewhere close to your head . For holding your mobile, or to shield your eyes from the sun, or to hold the camera steady while you're taking a picture.