Personaly if it was me I would just use the 5 incher since there was a concern with the Electronic Air Cleaner not being monitered, that way saves them the time of having to replace those 1 inchers more frequently, I know with elderly people up here they go with the larger media filters due to most of the furnaces being in the basements a lot easier on them.
Far better it is to dare mighty things, to win glorious triumphs even though checkered by failure, than to rank with those poor spirits who neither enjoy nor suffer much because they live in the gray twilight that knows neither victory nor defeat. (President Theodore Roosevelt)