questions about sororities here

Letters of rec are always helpful, but SFA isn't a highly competitive school. You can still get into a sorority without them.
All sororities at SFA require members to live in the houses except for XO which has a limited number of residents.
Check the SFA Panhellenic website for costs.

THe average cost of a sorority is 1300-1500 dollars, and I would say most fall there either rupfront or after added cost. And your first semester will probably be 1500 and after that 1300.
The cost of living in the house is around 3000 a semester, and that includes food. (now, I'm not saying it IS 3000, im saying that's a good estimate. maybe a little higher to 3500). Average apartment cost is about $600 a month so it isn't really most expensive to live in a house rather than an apartment and on campus runs you typically the same when you factor in food cost.

All houses make you live in the house aside from Chi Omega, but for the most part, you can usually (depending on the semester and number of available girls to live in the house) get away with not living in the house if you absolutely cannot/do not want to.

Sororities are super do-able, but save money! I paid for mine completely on my own, and saved some money the summer before I rushed, and it really helped.

Also letters of rec mean nothing unless they're from someone reputable in the sorority (Such as a province president or a recent alum that way popular/influential in that particular house at SFA) Other than that, I know people with letters on letters and get dropped from a house and someone with no letters gets a bid. At SFA, that isn't a big deal like at other schools. I would say if you know people, get some letters. If you don't- don't worry.