I've seen them allOn paper its fantastic, in practice not so much, but at that point it is too late... 

None of the above works unless you take action and put it into practice.

A house is always valued and appraised using residential practices which uses comparable sales.

I'm not saying you can't ask for it, but in a practical sense it likely doesn't matter on most small sales. 

I’ve seen different things out there regarding best practices. 

For all practical purposes, 100% bonus is dead, as far as I know.Depreciation, bonus or regular, starts when the property is placed in service, not when purchased and not when cost seg is done.

Build your knowledge base through books, podcasts, and online communities.

Is it customary that they have their process displayed online or in a pricing guide so I can shop around?

You can go to a local title company to run a quick title search for about $200 or you can do it yourself if your county records are online.

You can also check their reviews online at Google, Facebook, or Yelp.