PCI cards are FAR better than dongles for wireless connections.
You can always use the adapters than run the signal through your mains wiring, and these are faster than wireless, but can be quite expensive.
It is all above my head do you keep what i need in the shop I could call in tomorrow . have a chat !
Of course, yes we keep them in, think the PCI wireless cards are about £11, and fitting them is a two minute job so just bring the PC with you and we'll do it whilst you wait.
If you're just using the computer for general use then the wireless cards should be fine, however if you're using it for online gaming the difference in speed between wireless and wired can be noticeable so, as Mark says, the Plugs would be a better (albeit more expensive) option. The cost of the mains plugs varies depending on their speed and if they also rebroadcast the wireless network, so what you are using them for is an important point to consider.
General use and router not too far away - PCI Wireless card
General use and router at limit of range - Add higher db gain aerial
Low end online gaming on a budget - Faster wireless card plus db gain aerial
Online gaming general - Mains adapter plugs
Online gaming heavy - High-End mains adapter plugs
Online gaming nutter - Move PC next to router, use shortest cable possible, overclock the CPU, use your tropical fish tank as the cooling source for your overclocked processor.
Yes we have all that (except the fish tank