if those APs will be using for only bridging then i recommend is to configure them as autonomous
for below reasons :
1)those APs will be providing a link between two segments , so no need to centralized or unified it to WLC,
2) it's more simple to manage and to configure than mesh APs ,
3)avoiding any impacting on the link if any issues occurred on the WLC or the way between those APs and the WLC,
if you want to use them for client/bridge , then the unified solution is the best approach as it's really good to have all your wireless access centralized .