Here is one of many good sites for generally unbiased product research
http://www.timezone.com/
Many well known watch makers use `standard movements` produced by companies who only make movements. Although that said some swiss companies do make entire watch (including movement) from scratch.
I have an OMEGA Speedmaster - the only watch worn on the moon!! (not that I am going there any time soon...)
http://www.omegawatches.com/omega/wo_space_history1
Will last me until the day I die!!