Recommend speakers for a large living room

I am planning on moving to Montana and they have big spaces. I want to buy a vehicle and have $75,000, what should I buy?

That is about the same as your question.  What components are you using?  How loud do you listen?  What music do you listen to?  Given your statement, you are listening in multiple positions, do you intend to have a critical listening position, or are you interested in just having a balanced sound throughout the room?

If it is the latter, I would suggest you consider a set of Ohm Walsh 4000s and 4 subwoofers in a distributed array for smoothest bass throughout the room (something like Rythmik F15s, HSU ULS-15 MK2  or SVS SB 3000).  I would also invest in a few thousand dollars in room treatments.  The speaker setup will run you $10,000-12,000 depending on the subwoofers, all in maybe $15,000.  Put the rest of the money to use for something else.  

Thanks everyone for the response. Lots of great info here. I have reached out to MBL to organize a demo & am also going to check-out Ohm speakers next week. I hadn’t thought about adding sub-woofers. Question, if I were to add 4 sub-woofers, how would that work? Is there a pre-amp that could handle 4 sub-woofers?

You may want to consider speaking with Duke (Audiokenesis).  He is a well respected speaker designer and the first to offer a consumer distributed bass array.  

In regard to adding four subwoofers, you simply run each in mono.  If you were to use the Audiokenesis Swarm system, it uses a single amplifer for each subwoofer.  My only concern with using the Audiokenesis would be if it would have enough output capability given the size of your room.  Again, Duke would be able to answer that, as he also designs systems used in larger environments. 

http://www.audiokinesis.com/the-swarm-subwoofer-system-1.html

Audiokenesis response above is why it is worth speaking with a designer that does this for a living.  I completely missed that because of the size of your room, room modes are not much of an issue.  With the size room you have, you are really getting into commercial sound reinforcement issues where the experience of someone with that background would be very helpful.