A four leg position simulator:
http://www.888optionsnet.com/investigator_2/wi_positionSimulator.asp
An ok options calculator:
http://www.888options.com/resources/options_calc.jsp
An options sensitivities simulator:
http://www.ftsweb.com/newfts/opsens.htm
Another option calculator:
http://www.ftsweb.com/options/opbarr.htm
A 20 leg expiration calculator:
http://www.optionstrategist.com/free/analysis/calcs/expiration/index.html
http://www.888optionsnet.com/investigator_2/wi_positionSimulator.asp
An ok options calculator:
http://www.888options.com/resources/options_calc.jsp
An options sensitivities simulator:
http://www.ftsweb.com/newfts/opsens.htm
Another option calculator:
http://www.ftsweb.com/options/opbarr.htm
A 20 leg expiration calculator:
http://www.optionstrategist.com/free/analysis/calcs/expiration/index.html
Don Kaufman and others just reference what some of their clients do and what is a good probability of accomplishing with your option trading allocation. NOT your total portfolio.