OP, you mentioned that your income is over $50k, MFJ and have two kids. If you put as much possible in your 403b, esp if you can max it, you could be eligible for EITC and the retirement savers credits. Contributions to tIRAs won't work to lower your AGI for the EITC (they also test line 7 wages); in this scenario it is better to contribute to the 403b before moving on to the tIRAs.

My state also matches the EITC at 30%, so we save even more on both fed and state taxes. The phaseout rate on the EITC for us is 21%, so every dollar DH puts in his 401k makes us eligible for .21 more in EITC, .063 in state EITC, saves .04 in state tax and .10 fed tax, or 41.3% altogether. HSA contributions are even better, since they also save the 7.65% FICA, for a total of 48.95%.

Run the numbers to see if you can get your income in EITC range, and/or in Retirement savers credit range. Contribute at least $2000 to your 403b and to a tIRA for DW for the best return here.