Extending wireless range??

Hello everyone, been lurking this site for awhile but today is my first post.

I recently moved my home office into my garage which is about 250 feet away from my home and existing router. I have a 54 mpbs Trendnet wireless PCI adapter in my cpu and it would only pull 1 bar and not connect. I called my freinds at Tiger Direct and they suggested a wireless Netgear USB adapter with rangemax. Needless to say it went from 1 to 2 bars but will not stay connected. Just wondering what is the best and most cost effective way to extend my range.

I currently have a Netgear wireless G router(a cheap one), and another desktop is wireless with a pci card, all wireless G. I have broadband internet through my cable company. I also have an Acer laptop and all have excellent connection in the house.

1.Should I change everything over to wireless N? I read it has better range, but how would the existing "G' pci cards get along with an N router?

2. Should I get a stronger high gain antenna for my router?

3. Or a wireless range extender

4. What about going from 54 to 108 mpbs pci adapter?

I also have another cheapo Belkin router if that helps matters.

I did read through the posts but some of it was confusing. Thanks for all your help!

 

Wireless range extender gets my vote.

 

I see bad reviews on the range extenders. Does anyone else have a suggestion?