Inquiry about HiGain WiFi Adapters+Antenna to amplify reception signal

Collecting some kits for WiFi High Gain Reception offered in, ie eBay-UK :

http://cgi.ebay.co.uk/800mw-USB-wire...item3a57f8949c

http://cgi.ebay.co.uk/43dBm-Wireless...item19ba430cc2

http://cgi.ebay.co.uk/30dBm-NextG-US...item27af8f259b

http://cgi.ebay.co.uk/STRONGER-then-...item5634dc70d3

http://cgi.ebay.co.uk/Alfa-AWUS036H-...item562fb07cfd

http://cgi.ebay.co.uk/Yagi-19dBi-5M-...item5639e5dfdb

http://cgi.ebay.co.uk/TOP-POWER-21dB...item5639cd7476

I wouls like to get some consultance from some one smart in the matter, if some of the kits would be also able to encrypt protected private networks.

My aim is to engage to open public WiFi networks captable around, but I am near sure would gets moreover protected private ones.

I try to explain: I am not sure if true, but found other kits offered, it is affirmed that Adapters based on ie Chip RealTek 8187L 500mW, 2870, Alfa AWUS036h 1000mW, Cisco?,
are able to cr*ck protected networks, since designed for Auditing, WiFiSlax, useful to inspect- test their reliability, security,
for H*ck*rs when wished to link on other user networks.

In case statement above is true, I wish to know if Adapter component of this kit is able to do about same task?, better?, more powerful?.

Other indication?, suggestion?. What is according to you the better choose?, by keeping as prioritary (performances+reliability+encrypt)/price .

In case it is considered to propose a kit by swapping to a more suitable purposed adapter, can I receive indications on its composition, features, costs of single items?.

I hope it is clear my inquiry, otherwise am able to better explain myself, don`t hesitate to ask. Thnx, Rgds,