Ching, you do not need 802.11a/c now.. coz no hardware support that yet. The below are 2 routers I am thinking... you can try to ask for other opinion
Netgear WNDR4500
from other report strong wifi signal and good speed but also got some report say got issues of quality
Belkin AC1200 DB
new router with 802.11a/c but not true 802.11 a/c speed but price is quite reasonable... But some ppl say the speed seems dropped after using long time.....