I still own/have owned 1/2 of the speakers that somebody listed above.
If you post you want opinions on a speaker, 100 people will reply with a 100 different recommendations. IMO, start going to audio shows like the Tampa Show this weekend and you will see maybe 100 different speakers.
There are many speakers that are better than the kef blades for quite a bit less money. If you want some great sounding speakers for your room, used, you can pick up a pair of Revel Salon 2’s for $10k and would never need another speaker, then you will need a very good amp to power them. Look at the Usher BE10’s used for $7k, Usher BE20’s for $10k used, or the Totem Winds for $5k-$8k.
If you want something very close to the Kef Blades for 1/5 the cost, look at the Kef LS60’s that are active meaning they have the amps/dacs built in to the speakers. I’ve auditioned both speakers in the same largish room and I would buy the LS60’s. All you need is an Ethernet cable (or WiFi) and power to each speaker and you are done. Because you have a large room, I would also add 2 of the Kef subs which are easy to add to the LS60’s via the Kef app on your iPhone.