I used an old Linksys WRT-54G with Tomato firmware as a wireless bridge to connect my VSX-43; just got it working today with Airplay. I found my Linksys on the sidewalk in a rainstorm; you should be able to get one for a few dollars on Craigslist. Get V1 to V4; Tomato doesn't work with V5 or later. Wireless G bandwidth should be plenty for streaming.
See this thread for one problem I had and its solution.
If you can't find a WRT-54G I highly recommend the TP-Link TL-WR702N at $22 from Newegg. I have two of these functioning as a wireless bridge in my office and they have been rock-solid for almost a year now.
I know it's been a while since you posted your question but if you're still looking for a solution one of those might help.
Pioneer Elite VSX-43
2X Bang & Olufsen Beovox S75
|Pioneer Vsx 1022 K 560w 7 Channel A V Receiver|
- Supermicro PWS-561-1H ATX12V & EPS12VRating: 0.00
531 ReviewsMore on PWS-561-1H ATX12V & EPS12VPrice: $134.05Supermicro PWS-561-1H20 ATX12V & EPS12VRating: 0.00
531 ReviewsMore on PWS-561-1H20 ATX12V & EPS12VPrice: $134.05Supermicro 560W High-Efficiency Pwr Supply 80Rating: 0.00
531 ReviewsMore on 560W High-Efficiency Pwr Supply 80Price: $310.76