I am not yet sure of the distance/range I’ll get from a new Extreme Base Station. It may be that I need an Airport Express.

As the base station will be in a central location, can I use 2 Airport Expresses, one on opposite sides of my home so that both distant ends of my home have coverage?

Or, is there some other way to maximize the signal strength and distance? If possible, I would prefer to stay with Apple products, but that is not a hard & fast requirement.

Yes, you can use both Extremes and Expresses (more than one) to extend existing networks, including that of an Extreme base station or any other WiFi router. It’s a setup option; follow the prompts after selecting this. Your Extreme manual may have some info on it; alternatively, search Apple Support for ‘extend network’ or ‘Wireless Distribution System’(WDS).

Many thanks. I was just concerned (worried) that somehow having 2 Expresses would either conflict with each other or degrade the overall performance.

Now, it's just a matter if sucking up to Santa.

if you are going to run a cat5 to both of them to provide access, then having them as far away as possible (as long as there are no dead zones made in the middle) is fine.

If you're going to be running cat5 to one and extending (WDS) to the other, place one 1/3 from one end of your house and the other at 1/3 from the end of the other house for optimal performance, if possible.

V1, My plan is to use only WDS, no Cat 5/6.

FWIW I have had good success extending my Airport network using multiple Airport Expresses set as WDS.