Best Smoke and CO detectors, and where to buy?

[Samantha Soto]

I'm getting way too caught up on the details here I'm sure.  I didn't imagine choosing smoke and carbon monoxide detectors would be so hard!  I wanted to get dual detectors that have sealed 10 year batteries, and also would love a reasonable price.  What brands do you guys use?  Are you happy with them?  I want something that won't go off randomly all the time and drive tenants crazy.  Also want something that won't break the bank.  Anyone know where I could order in bulk instead of having to buy one by one?