Temperature sensitive mutants

[ZOOMmmm]

  Soon, I'll be trying to create some temperature sensitive mutant
bacteria.  I'm hoping to use E. coli, but don't know yet which strain to
use.  Which strain is best suited in creating ts mutants?  Also, how good
is making ts mutants?  I've heard they tend to revert back to normal.  I
hope to have some valuable incite before I start to make these mutants. 
Please e-mail to my address. Thanks.