Like to drive fast and comfortable don't usually combine together. Fast cars are usually not comfortable, though comfortable cars can be fast, but they cost a lot more than your budget.

If you like to drive fast then the Preve Turbo will give you that but it is above your budget. The low spec Preve may not give you the thrill and power.

You are still young at 21. Just start off with a decent car. Any of the cars above would do fine. It just depends on your budget. Preve's fuel economy is not very good compared to the other two, so if you want something that isn't too damaging on your wallet, better take the Saga, especially if you do a lot of city drive. A lot of people drive Perodua Myvi because it is quite fuel efficient. It may be common and cute, but when it comes to pumping petrol(RM500/month on Preve vs RM250/month for Myvi), that may be a factor for some or most people.

look out for maintenance also.
preve is a very costly machine to service.
CVT fluids cost more than MT fluids.
roadtax and insurance also need to take consideration.

good luck bro...

my first new car was myvi 1.3 manual...and i was wayyy over 21.

p/s: base on my experience last time, scouting for used car is easy (thru mudah.my of course !) but closing the deal was very, very difficult. most will require higher dp. some just dont layan u.so end up buying new cars. maybe its just my luck.