Guidance Request - Allergies, number of purifiers and type, ideal placement within home, furnace filters, and low running costs

I appreciate anyone who takes the time to help me find the right product, my nose thanks you!

I live in Canada and won’t be able to see an ENT for 6 months and I am having a hard time breathing, I haven’t had allergies before in life but the last year had been getting progressively worse. It goes away on my dairy walks in nature so I am thinking it’s something in my house? Maybe dust?

My furnace filter is 25x20x5 and the highest MERV filters I can find are Merv 11 (3M filtrate) - if you know of others let me know.

I don’t mind spending a little more money on the initial purchase as long as filter replacement are relatively infrequent. I heard Winix may be the way to go for this?

Other considerations -

Low sound on lower modes but can still filter rooms adequately

Possible Smart Control so I can turn on all the purifiers an hour before coming home on full blast then reducing when home

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Living room is 280sqft (north eastern wall eastern wall open to dining)

Dining room is 105 sqft (open completely to kitchen on the south and living room on west)

Kitchen is 130 sq ft (open to dining room in the north)

Bedroom is 133 sq ft

Office is 113 sq ft

Should I have 2 units for the living room?

What is the optimal placement for the layout of living , dining kitchen?

What are the recommended units for the smaller rooms (bedroom and office)