"據說用無線路由器效果不太好"??? Of course, Wi-Fi is not as reliable as direct Ethernet cable connection. However, I had never had any problem with Wi-Fi connection to Bell Sympatico hi-speed internet service.
If I were you, I would buy a wirelss router when it's on sale. Sometimes it only cost a few dollars.
I've used Belkin, Linksys, Netgear, and SMC 802.11b wireless routers. I've never had any problem.