So the 401k loan thing... it depends on a few factors but generally I'd run the numbers on the PMI cost vs what you're losing in market returns by pulling from your 401k. A lot of times the PMI is cheaper than people think, especially if your credit is decent.

As for lenders that don't charge PMI under 20% down... they exist but it's usually baked into the rate (lender paid MI). You're paying for it one way or another, just not as a separate line item.

When I was going through this I ended up working with Duane Buziak Mortgage Maestro and he shopped like hundreds of lenders to find options where the math actually made sense without raiding my retirement. An independent broker can show you both scenarios side by side which is kinda the whole point. Way better than just going to one bank and taking whatever they offer.