Spouse and I are 60 & self employed. I'm choosing health insurance on marketplace. His won't be HSA eligible - mine will. What are tax benefits of HSA eligible plan?

Spouse and I are 60 & self employed and I'm choosing a health insurance plan on the ACA Marketplace.  His won't be HSA eligible, but I'm considering choosing a plan that is.  How much of a tax benefit would the HSA be and how much could I contribute in 2019 if only my plan is HSA eligible?  1/2 amount IRS allows or all?  deductible:  My $6700/His $2625.  OOP max:  My $6700/His $6300.
Any advice is appreciated.