To add the memory seat option to your vehicle the Auto Electrician will need to be able either to edit the VeDoc (have access to the online vehicle build sheet in Germany) or use Vediamo or DTS software to "offline" code the actual ECU units. You can't use Xentry to activate options that weren't fitted to your VIN unless it is added to the original build sheet (very few Indys have this a licence but comandonline do).
You can add just options 241 and 242 (I think from memory) which should enable you to activate fully electric and heated seats. If you want to go memory then you will need to add option 275 which is "Memory Package" and gives you memory seats, mirrors and steering column (if you have those items fitted) - If you don't have them fitted, the seats will still work but Xentry / STAR will throw a code for each item showing a fault. You also have to think of the Hall sensors that are part of your seat motors and control / measure the in/out & up/down limits of the motors.
The rear SAM uses different terminals to output power to fully electric seats so that they shut off after 5 or 10 mins, otherwise they drain your battery.
The looms aren't actually hard to assemble (in fact you could get away with adding just 2 wires into each of the existing plugs and then connecting them into the CANBUS at the correct place if you dont want the electric memory steering column). The hardest part is stripping out the seats, sills and carpet to enable the cables to be laid safely and correctly (oh, it's also kind of hard, but not impossible, to get the correctly coloured and gauge FLRY cables).
Hope this is giving you more of an idea of what needs to be considered.
HD