Which clear finish for Cypress Porch Ceiling?

I'm doing a Cypress ceiling on a Porch (390 sq. ft.) and I want to leave the cypress natural.

I'd like to avoid the initial yellowing associated with oil based products. I've been searching the net for water based alternatives. I've found a few, however I have no experience with any of the brands let alone the specific products.

Some candidates I've found are:

Varathane Water Based Diamond Spar Urethane

Zar Water Based Exterior Polyurethane

Defy UV clear epoxy resin

I'm open to any suggestions, especially if you have experience with a specific product.

Thanks in advance.

Ryan