Looking for a house we could house hack, had an incredibly low interest rate on mortgage and house has increased in value about 42%, an estimated 180k in equity.

Get an estimate from a GC to get a good idea of what is required.Market Comparables: Check what similar-sized homes with finished basements or additional bedrooms are appraising for in your area.

I’d estimate it to fall between $200k and $400k.

Always recommend doing a soft-pull especially since not sure exactly when you'd find a property but you can get qualified and get some estimates.  

Estimated costs range from $500–$1,000 annually, depending on the complexity of their LLC and rental activity.For Partner 2 ($148K joint income, W-2, 1099 income, 1 rental, 2 kids), a CPA is strongly recommended.

Compare other rentals with a similar size, location and bedroom count to get an estimate of what the rent would be while you're living there.

Additionally, the estimate for my tax preparation for this year was approximately $1,000 over the cost I paid last year (including the time I paid for them to correct their errors).

Is $800k a good estimate (~ $73k door)?

Again i believe it is my best estimate of actual sustained maintenance/cap ex in my market.I did an estimate about 1,5 years ago on a emerald coast 3/2 condo with class a interior finishes and came up with $300 for just the interior (class a finishes cost more).  

I'd estimate your cash flow after you pay the loan payment would be $600-$800, which a lender that understands investment real estate should give you some credit for on your DTI.As for a bank, I have a specific lender at NBI that I would recommend.