Unless you are putting down a significant chunk of money I'd really just suggest you go with a 30-year fixed, you don't want to be caught in a situation where values have declined and you are in an adjustable rate mortgage where you need to refinance but perhaps can't because mortgage qualifications have tightened up or you don't have as much/enough equity.
52% debt ratio can qualify if there are good compensating factors (strong credit, good down payment, good reserves), so it is higher than normal, but not out of the question to still be able to qualify. What is odd is that the 52% figure was given, such an odd number... automated underwriting approves debt ratios up to 64.99% as an FYI.
You might still be able to both be on the loan and use an FHA loan as the purchase - that would be an option I'd look into if your wife can't qualify on her own. 1 late in the past 12 months, with somewhat decent credit scores (630's is decent), still has a good shot of qualifying.
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