It’ll come in handy to someone at some point, when i go searching for info i glean a lot of other useful info when people talk around the specific topic (as long as it’s not too far off topic).

With that in mind i just looked up the 13A package sizes in the datasheet and… spotted the ‘U’ ‘H’ leg info, d’oh!
But packagewise:

PU comes in what Atmel call the 8P3 package, which they specify as: 8-lead, 0.300” Wide, Plastic Dual Inline Package (PDIP).
The legs go straight down at 90 degrees to the body so would need to be bent to fit on a driver board. The size of the body, not including legs is: 0.365 x 0.25 inches (nominal).

SU and SH come in the 8S2 package which is specified as: 8-lead, 0.209” Wide, Plastic Small Outline Package (EIAJ SOIC).
The legs are shaped to fit a driver board and the body size is: 5.35 x 5.40 mm (maximum). (Handily the datasheet switches from inches to mm for the measurements and omits the nominal stat.)

SSU and SSH come in the 8S1 package which is specified as: 8-lead, 0.150” Wide, Plastic Gull-Wing Small Outline (JEDEC SOIC).
The legs are again shaped to fit a driver board (as the gull-wing moniker would indicate) and the body size is: 0.4 x 0.5 mm (maximum).

There is also an MU which comes in a 20M1 package (20-pad, 4 x 4 x 0.8 mm Body, Lead Pitch 0.50 mm, Micro Lead Frame Package (MLF) )
and an MMU which comes in a 10M1 package (10-pad, 3 x 3 x 1 mm Body, Lead Pitch 0.50 mm, Micro Lead Frame Package (MLF) ).

Further, there is SN in an 8S2 package, SS7 in an 8S1 package, SF in an 8S2 package, and MMF in a 10M1 package. These are all rated to handle slightly higher temps than the above.

The leg info is:

H or 7: NiPdAu lead finish
U, N or F: matte tin

And if there is an ‘R’ on the end it denotes: tape & reel.

Phew!