I am doing a search for lights for my trailblazer so that I dont have to modify it when I get there, I am looking for these style of tail lights with the amber in the middle which are OEM japanese
 

where in the UK are you going to live?
there is another option if you cant find the taillights you're looking for, i usually put chrome/amber bulbs in the reversing holder but connected to the blinker wires,

if you're anywhere in east anglia drop me a email or pm, your truck will need a SVA test if its less than 10 years old, i can help you with tips on how to pass, there are companies that will do it for you at a price but its not that hard or expensive to do yourself let me kow if i can be of help

eamonnschevy Norwich Norfolk UK  

Hey Eamonn! I knew you'd jump in and offer some help. I'm not familiar with the regulations in the UK, so I'm glad someone with some knowledge could comment. Thanks!    

Anyone else know of where I might find the amber rear lights for the trailblazer?  

Eamonn would probably know.