Actually, there isn't much difference in performance between a card and a dongle. Did you get a dongle with an external antenna? If you did, just get an 8dBi antenna
If your dongle doesn't have an external antenna, then your particular dongle is the problem. (unless you're using XP, which sucks for wireless connections) I suggest this one: http://www.newegg.com/Product/Product.aspx?Item=N82E16833166055
(I have one of these, and it works great)
Also, check and make sure that the router is a wireless-N capable router. If it isn't that could also be the problem. I suggest this one as a decent inexpensive router: http://www.newegg.com/Product/Product.aspx?Item=N82E16833166039
(this I also have, it's very good)
However, if you're dead set against a USB adapter, here are a PCI-E and PCI card. The PCI-E one.
| The PCI one.