Help with Cedar soffit ceiling and columns

Hello, we are building a new house and i opted to do some of the exterior wood finishing myself as then i can have better control over what and how it goes on and how i need to maintain it. 

We live in eastern south dakota,  harsh winters and hot summers, we will have 8 6x6 cedar column posts on front porch columns and then a cedar ceiling in this porch area,  I sanded all of the ceiling boards to 100 grit,  I love the tone of the natural wood color when wet, and am wondering if anyone has experience with a varnish or clear sealer, on an exterior porch ceiling that wont get any direct sun.   I know a film finish will peel in direct uv sunlight and i dont want to fight that but i think it may hold up well as it will be shaded for the ceiling boards.  If its going to peel then id just stain, but any real world experience over time would be appreciated advice on the cedar soffit/ ceiling.  I would like to not have to stain the ceiling every couplee of years, being a ceiling but if the film is going to peel i would rather stain than have to sand that off in 4 years.  also i do a lot of Fish replicas and finish them with automotive topcoat.  Does anyone have experience on what that would do in an exterior setting on wood.  I have finished desks and benches with it interior and it looks great, but im wondering if it would be too rigid for a moisture ridden environment

 for the columns i  am planning to stain the columns which will get the eastern exposure and full sun on the columns.  for all my research i am thinking the defy ultra cedartone or the twp100

please advise if you think either of these or a different product would be best suited and why.   Holding Color is probably the most important thing to me, i wont mind staining these every couple years, but ideally id like the longest lasting protection here as well

Tyler