Even though term rates have been slowly going up since the recent financial disaster, it is still the way to go. Purchase $1M of 20yr term for you & $500k 20 year for wife. Owning multiple policies/laddering might not be very cost effective as you have to pay multiple policy fees and might not hit the pricing bands/breakpoints.

Make sure it is convertable for the full 20 years without proof of insurability so that you can continue coverage after the 20 years if needed and/or health changes.

Use a broker/agency that has access to multiple carriers (10-15) as all of them look at your health differently and if the cheapest carrier sees you at Std risk another might see you as Pref and they can easily move your info over to other carrier.

No matter what sales pitch or pressure you might get to go with permanent product, it shouldn’t be necessary. Better to buy term and invest difference or use the difference to purchase DI or LTC coverage.