I know this thread took a bit of a left turn from the first post, but I thought sharing my ideas could potentially be helpful for future searchers
Being a local sorority, when we felt ready to secure a chapter house, we began by driving around neighborhoods around campus and taking note of the addresses of the houses we liked. We then found current or former residents via FB (back when it was commonplace to list your address) and everyone was really friendly and offered to give us tours of their places. One of these happened to be a former fraternity a little ways off campus--turns out that one guy listed as living at that address was from my hometown, so he gave us a tour, and the place was perfect for us. He was graduating anyway, and the rental company was thrilled that the house would finally be fully occupied, so we signed a long-term lease. Obviously if you're a national, your HQ will probably take care of most of this, but we didn't find it too difficult as a then quite small local.
As for living in during senior year--I did, and I loved it! The previous year we'd had 10 people in a cramped rental (mostly, but not entirely, sorority members) so the space was much appreciated. Since we kept records of participation points (for attending events) and also took seniority into account, I was able to secure one of the two singles with an adjoining bathroom, so I had the perks of a roommate without actually having to share the room itself. My suitemate and I didn't know each other well before we moved in, since she was so busy with fitting her undergrad into 3 years, but we became really close, and I'm so glad I had that opportunity to get to know her. And since the house capacity is around 25, it was big enough to avoid anyone you had drama with, but not so big that it felt like living in a dorm (like some of the houses at IU--I heard Tridelt has 100 living in, and that's one of the smaller ones?!). Granted I was one of those who wanted to "live it up" my senior year, but my suitemate was working her tail off to finish her degree and she still loved the live-in experience. So if anyone's in that situation, I'd highly recommend living in if space allows!