for Rus chain, best variant imo would be to start with wooden churches and finish with stone cathedral, as most major Rus churches were made of stone.
You can chose one of two main styles: either use Byzantine-like style (Kiev architecture), an earlier one.
St Sophia in Kiev (ancient design, current cathedral was rebuilt in modern style), built 11 ad
Church of the Titches destroyed by Mongols (built 10 ad)
On the other hand, Vladimir-Suzdal "northern style" had distinct white walls. At appeared much later, with the decline of Rus princedoms
Assumption Cathedral in Vladimir (~12 ad)