I would HIGHLY recommend the D-Link DIR-655. They're usually available in big box retailers for $129, sometimes lower (the list price is $149).
This is an 802.11 pre-N router and gigabit switch. If you ALSO get their matching network adapters you can run wirelessly at a max of 300Mbps, and your wired connections will run at 1Gb.
Now, this doesn't mean that your INTERNET connection will go that fast. You're still limited by the speed throughput by your cable modem. Some of these are getting pretty fast, but as far as I know none of them run at 300 Mbps, at least not in the United States.
Where you CAN run that fast is in transfers between computers connected to your home network. The final throughput speed on your wireless connections, however, is dependent on the location of your computers relative to the router. Speed falls with distance and obstructions between the NIC and the router. As a general rule of thumb, however, the faster the maximum speed, the greater the distance over which you will have a usable connection.
D-Link promises that its firmware will be upgradeable to the final N standard.
This device is very versatile and is VERY easy to configure. It provides the highest level of security. D-Link also provides genuinely EXCELLENT telephone support should you run into snags.
Your problem with buffering may be on the outside of any home router you may wish to purchase, but if you're still using an 802.11b router then there's a good chance that a faster router will solve many of your problems.