Purchasing an AP.... Need Help.

[MAULxx]

I'm going to be purchasing the Roku HD XR box & I want to stream both SD & HD content wirelessly from my bedroom to living room through 2 walls approx 20 feet distance.
I have a nice D-link "wired" router DGL-4100 that I currently use & would like to continue using.

I have always had a wired connection to everything so I'm a bit lost as to what AP I need. I would like set-up to be as painless as possible. Would it be better to stay with D-link for the AP?

Roku recommends these routers & Access Points.

WBR-2310 RangeBooster Wireless G router

DIR-655 Xtreme N Gigabit Router

DWL-2100AP AirPlus Xtreme G High Speed Wireless Access Point

EBR-2310 Ethernet Broadband Router

DGL-4100 Broadband Gigabit Gaming Router

DIR-825 Xtreme N Dual Band Gigabit Router

DIR-628 Rangebooster N Dual Band Router

DIR-615 Wireless N Router

DIR-600 Wireless 150 Router

DIR-655 Xtreme N Gigabit Router

DWL-900AP+ Wireless B Access Point

The Roku HD XR works with 802.11n. Do I need 802.11n AP for this set-up?

Please advise me on some APs. Thanks.