networking help

[DFSniper]

i'm getting semi-mediocre connection on my computer (those who have me on AIM have probably noticed the constant logging in and out). i was looking online, and i saw something about using a second router as a wireless connection (click here), but i still have a few quesions. here's my current configuration:

belkin wireless g router in dining room
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distance of ~175ft and 3 walls
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my pc w/ linksys wireless g/w speedbooster card

i get about 50% signal strength and an average connection of 5.5mbps (never more than 11mbps).

if i were to get a 2nd router and use that instead of the wireless card, would i get a better signal?