The XPA-3 is an amp with a fairly good reputation here on the forum. I almost bought it but got the Outlaw 2200 x 3 instead (the XPA-3 was recently out of stock).
You'll get the most improvement in your system by budgeting for a speaker upgrade first (before amps and before a new receiver). In other words, don't move budget from speakers to anything else until you can afford the speakers you want/like/need.
By the way, the speakers you are looking at were all on my list at one point. My signature is what I ended up with.
Of note, your room is 1,000^3 larger than mine which is why, at the last minute, I changed from an F15 to an F12. I figure I can always double it later if necessary.
What speakers do you have now?