Dongle or bridge? - Hardware advice for a 3 floor home?

Hi - I'm so happy to have found this forum. Please forgive me if I give too many or too few details, i'm new

I hope you can give me some advice about wifi in our 3 floor 1950s home (basement, main floor, bedrooms upstairs). The basement family room is where we watch TV and have the main computer. The TV (via PS3) and PC are ethernet wired to our ISP's Bell 2wire 2701HG-G. We use Serviio DLNA Media Server.

In our bedroom on the top floor we want to set up our BDP S370 for watching TV and streaming video from the PC in the basement using Serviio. The Sony Dongle UWA BR100 is expensive and I want to know it's the best choice before ordering it. Would it be better to use a bridge/access point upstairs something like the TP-LINK 300Mbps TL-WA901ND ? I have used wifi on our laptop, kindle and ipod on the top floor. It seems a little bit slower but not very noticeable, however I am worried that streaming HD may be a problem. BandwithPlacedotcom shows this as our numbers on the main PC in the basement:

Download Speed: 4948 kbps (618.5 KB/sec transfer rate)
Upload Speed: 643 kbps (80.4 KB/sec transfer rate)

Advice and/or suggestions?
Thanks!

Corrine

You could always wire it for Ethernet and drop access points?

But wouldn't that require running an ethernet cable up from the basement modem? I really want to avoid that.