If your wife is a school teacher, there are some other issues to consider as well.  One is whether or not she will be in a higher tax bracket after retirement than she was before.  This can happen depending on the size of the 403b contributions, any pension she may be eligible for, and eventual social security income.  It can become more complicated yet if her pension reduces her social security payments, or if state taxes are waived on the pension income.  The reason for raising these issues is that there may be a case for using a ROTH rather than a traditional IRA.  Or it may later become an issue when partial ROTH conversions from a traditional IRA would be beneficial.

I apologize if I'm making this more complex than it needs to be, but teachers in particular often have unusual considerations relative to many other professions.  You may have guessed that I'm a retired teacher...