Rantepao's small airport has flights Tuesdays and Fridays from Makassar via Merpati Airlines for Rp.210,000. Be warned though that it is possible the flight could be cancelled last minute due to aircraft maintenance or insufficient passengers.
From Makassar, you can reach Rantepao by coach bus with Metropermai (located on Perintis Kemerdekaan) for Rp140,000 (May 2015 price), leaving daily at 9am or 9pm. These busses are comfortable and air conditioned, allowing you to use them for a night's accommodation. Your hotel can reserve you a seat. Note that this departure location is closer to the main city than the Terminal Daya option, which offers faster kijangs, but ultimately both options should take you ~8-9 hrs with traffic.
From Sengkang you would need to travel by bemo to Lawawoi first (30.000rp June 2015). Tell the driver you want to go to Rantepao so he will drop you off at some intersection where Kijiang pass that will take you to Rantepao in about 4-4.5 hours. Cost 70.000rp June 2015
Scooters are easily arranged for in homestays. There are also several rental places but they will usually require the motorbike be returned by 17 PM if you rent per day. Usual price is Rp80k per day. (July 2015)
Rumah Makan Ande (A cheap and delicious local Indonesian restaurant. Lovely woman that runs it. Look for big red and yellow sign.), (on Jl Diponegoro, a stone's throw from Jl Ahmed Yani (the main drag).). Rp 15000+). edit
Wisma Monton, Jl. Abdul Gani 14A. Double rooms for 150,000 Rp (Oct 2015) with western toilet and shower. Includes breakfast (ask for an additional telur) and free water refill. As good wifi as you get in Rantepao.
Riana Homestay. Small family-operated home stay with 4-5 spacious rooms. Hot water shower with good pressure, good WiFi, clean rooms with fan and friendly hosts. Simple breakfast included & motorbike for hire available. Rp150,000-300,000 depending on season and your negotiating skills. firstname.lastname@example.org, +6281 343 696 270
Hotel Pison, Jl. Pongtiku No. 8., Clean & spacious rooms, hot shower, balcony, free WiFi, great restaurant, helpful & friendly staff, rp. 120,000. Slightly out of town (10 min walk to main centre). Beside Pia Poppies hotel (another decent option. Very quirky.)
Toraja Heritage Hotel, Jl. Kete Kesu, first 4 star hotel in Toraja, superior and deluxe rooms are in a traditional Torajan house (tonkonan)
Wisma Maria 1. Simple cheap hotel well located. Rooms a bit tired, some missing toilet seats, but relatively mosquito proof, and clean. Rp115,000 to Rp220,000 depending on single/double and hot/cold shower. Breakfast choice is: no choice. You get eggs and home baked toasts with home made jam, fruit juice. Local guides will come in the morning to find clients - prepare to be 'hunted' for. Scooters available for rent.
Pia's Poppies. Rp176.000,- decent spacious rooms, no AC, some of them with mosquito net. Free wifi in the restaurant, breakfast is a bit pricey for what it is, otherwise good value. Only 10 minute walk from the center. Welcome drink.
Buses to Tentana (13hrs, Rp170,000 - July 2015) run from 8am from the main drag. Buy tickets the night before, by 8pm from one of the only two companies that service this route (Rappan Marannu, or Ketty).