Upgrading to 802.11n on older Mac Mini

Question

I have 2007 802.11a/b/g Mac Mini Intel Core 2 Duo and a few questions:
1) How can I get 802.11n on this machine?
2) How much improvement will I see going from a/b/g to n?
3) Will this enabler do the trick? http://store.apple.com/us/product/D4141ZM/A
4) How about this USB adapter? http://eshop.macsales.com/item/Newer%20Technology/MXP2802NU2C/
5) How about getting a Airport Express and connecting to its Ethernet port?
Any and all suggestions would be appreciated!

Answer 1

2) How much improvement will I see going from a/b/g to n?
What you do will determine if you'll see any improvement. For example, if you're only surfing the net, checking email, you may not see any improvement as your speed limit is with your ISP and not Wi-Fi. Many people have "basic" broadband which is less than 10Mbps. This is around 802.11b speeds. So upgrading to g or n will not get you any improvement.
If you're trying to share files between multiple computers within your own LAN, then you may see an improvement going to n. But it may only be noticeable with moving very large files. (i.e.: movies instead of Word documents.) Potentially it could help if you're viewing movies in the iTunes library on another computer (since it's all on the LAN and not through your ISP.) Listening to music from another computer uses less bandwidth so you likely won't see any difference between g & n.
4) How about this USB adapter?
5) How about getting a Airport Express and connecting to its Ethernet port?
Either could get you 802.11n, if you need to speed up your LAN. The USB adapter is straight forward, but it does require you to add a driver. Newer Tech's website shows the driver for 10.3, 10.4 & 10.5, but doesn't specifically mention 10.6.
Airport-to-the-ethernet port would work and wouldn't need drivers, but does require some skill configure...at least require a willingness to try. It's not that hard, but many people are put off by networking.
Me personally, I'd prefer not to have to install drivers since a future OSX update could affect the driver. So I'd be going with the Airport-to-ethernet option. (Actually, I'd be going with wired since you'd get 100Mbps or 1000Mbps (depending on the equipment), which is as fast as the real-world speeds you get with 802.11n (or faster) and has much less configuring than Wi-Fi and less susceptible to radio interference, and I do move very large files to the server on my LAN...but that's just me. )