My husband and I have more funds to put away towards retirement...

Background/Details:
We are 33 & 29, he works and I do not. He makes approx. $50K or so, contributes the max (9%) to TSP(Military 401K), we contribute the max to Roth IRA and a Spousal Roth IRA. We also have a healthy emergency fund. For tax purposes he is considered to be contributing to a pension plan. Our only debt is consolidated student loans at 4% and 3.5%.
Biggest Future Plans:
Most likely purchase a home in 3-4 years when we return from Japan. We just started saving for the downpayment on the home and will steadily continue to do so for the next 3-4 years but there is no rush to have it saved before that time as we will not be in the US. No children and no plans to have any at this time.

What do the Fools here believe are our next best steps to save for FIRE? Since we contribute the max to the Roth IRA we can't contribute any to a Traditional IRA, right?

Thanks in Advance, Gaia=)