[Elecraft] K3S Upgrades

[Geoff]

Perhaps a simple question but I am a new Elecraft user.

I have a 10 Watt K3S, (obtained pre built) together 
with*the****following three upgrade options ready to be installed; *100W 
automatic antenna tuner (KAT3), 100W PA stage (KPA3) and 2m option (K144XV).

Is there any preferred order to install them? Left to my own devices I 
would probably start with KPA3, and finish with the K144XV, and I am 
also wondering whether to re-assemble and test between the addition of 
each module.

Thanks,

73, GeoffG1WRH