I love cask conditioned ale - I've done it here with my corneys by naturally carbonating in the keg. I know it's not really the same as an oak cask, but it's still great beer.
I only think I've had oak aged beer by one brewery.
The reason a hand pump is required instaed of a tap is because with out force carbonation and CO2 hooked up then there is no way to serve the beer. A pump is required to draw it from the cask.
Believe me you can get Bad Cask condition Ale in the wrong pub!
Take a look at our Wiki. It's all there!
https://www.homebrewtalk.com/wiki/index.php/Casks
Yes mini kegs will allow you to have authentic cask conditioned ale.
It's unpasteurised, it's naturally carbonated and hopefully it will be a quality product.
You can negate the beer engine (Hand pump) because it is gravity fed.
The only problem you may have is the lack of head.
The beer engine forces som of the CO2 out of the beer at the glass to give a head.
Check this out as well.
http://www.cask-ale.co.uk/realale3.html
http://www.ukbrewing.com/
I advise looking at the catalogue on the last link for good pictures of all the "bits"
Here's a cask.