Mark, your first link (spd1) points to an SPD2 (not spd1) device, and the second link is broken.
Here are SPD Type 1 devices:
Type 1 Surge Protection Devices (SPDs) are mounted on the line side of the main electric service entrance panel (between the utility pole and where the electricity enters the service panel), as well as the load side.
www.spd-depot.com
and here are SPD Type 2 devices:
Type 2 Surge Protective Panels are mounted to the load side of an electric service panel and protect against residual external power disturbances as well as internally generated power surges, such as those caused by the OFF/ON switching of pumps or motors.
www.spd-depot.com
You probably should consult an electrician (or even better two) to see which one your home needs.
and here some high-level overview of what is spd and its types:
FAQs about power surges and protective devices to protect your operations and equipment
www.spd-depot.com
The bottom line is devices like Powerstrips and MRX 740 8K you mentioned are level 3. The latter is unnecessarily expensive and only protects a small subset of electronic devices in your home. Install whole house protection and you'll spend your money more wisely and with long-term benefits.