What are the different types of prepaid sim cards available in Petaling Jaya (Malaysia)?

Im from overseas. Will be in PJ for about 3 mths. Which telco offer prepaid sim card that has more talktime and sms either in Malaysia or to overseas? And what happen when the sim card is out of credit? Will I still receive free incoming calls and free incoming sms? And if yes, what is the maxmum duration of receiving free incoming calls and free incoming sms before I have to top up the sim card?