I believe the only difference the two is just the Cobb 11 is an updated version to Cobb 5. I forget off hand what the difference is, the Cobb 11 uses something slightly different.
Cobb method is probably the best method out there, unlike the Kuchera or the 10:1 maps, the method takes into account many different variable, including DGZ and lift.
Max T in profile can be good, but misleading.
For bufkit I download all my profiles from
http://www.meteo.psu.edu/bufkit/CONUS_NAM_12.html
I'll have a list saved in bufget so you can just grab the data with one click of the button. If you change the run time to latest, you'll get the most recent data