For hilly roads, it is best to use manual gears car so that you can utilise engine braking more effectively compare to auto gears car.
Anyway, since if you are not familiar with manual, an auto gear sports car is good enough. Just remember to drive slowly on bumpy and hilly road will be safe so no need to worry of not suitable to get sports car. Anyway, sports car has better brakes system compare to our daily driven car so it is an added advantages.
The only disadvantages of sports car is it is 2 door car and for auto on long distance drive Seri Aman to Kch regularly will get you fuel consumption higher (comparing 4 speed auto to a 6 speed Getrag Manual trans from the supra.)
For the RX7, it is maintenance that put this kind of nice beautiful car into bad pricing else this kind of car sure will have better value as it has cheap road tax, lighter car, sportier looks, etc.
RX7 used condtion normally starts at RM60K to RM80K range. Anything sell above that price range is subjective to worthiness of the car body and modifications comes with the car.
Anyway, found the advertisement RX7 for sale in Sarawak:
1.
http://www.mudah.my/Madza-RX7-FD3S-3996719.htm
2.
http://www.mudah.my/Rx7-4272678.htm
Older generation of RX7 FC:
1.
http://www.mudah.my/Madza-Rx7-Fc-4075667.htm
P.S.: Hope that helps you in making decision of choosing to buy.
If you get the Supra, its got a nice cokpit for the driver and got lots of space to install gauges
YouTube- Full Defi gauges in Supra