just a quick word on the version numbers.
the 1.xx will change. whats important,is the 3rd set of numbers,wich can be xxx or xxxx
.3= developer version
.3 =htc europe
.5 =wwe asia
as the builds progress,the first 2 sets,and the last number will become numerically higher,but the third set will stay constant.
not sure of exact builds for att& sprint at the moment,but...
att will be x.xx.502
sprint will be x.xx.651
you can use this thread to unlock:
The HTC One root thread
check the international one forum on xda for roms,the AOSP roms will be in "original android development" section. xda
just holler if you have questions