Offering deals with more detailed info and accurate numbers is something I am looking for from a wholesaler. 

The due on sale clause generates a lot of debate on biggerpockets, but me and my colleagues have yet to see a performing note (a mortgage that is getting paid) get foreclosed on based upon that clause.

Being able to accurately assess the ARV is the life blood of a flipper and wholesaler.

Myhousedeals has a buyers list you can be that is pretty accurate! 

I own a performing duplex and have successfully flipped one single-family residence.

To me the numbers don't look bad assuming they are accurate as far as rent, etc.  

And adding a clause subject too tenant providing new mailing address and employment location so incase they don't pay I have the judgement already but it's no good unless personally served so I would need accurate location of tenant which if they provide in court in front of judge should be accurate and upheld.

You can find them here on BP (set up an alert for "Baltimore", as Ned suggested) or by networking with other investors at meet ups and asking for referrals.A good investor agent should be skilled at understanding ARV and pulling accurate comps, be able to see the potential in a home instead of focusing on its current condition (which is why investing/construction experience is so important), and have a strong network of wholesalers to help locate off market deals.Gabriel is correct in saying that an agent will want to vet you as much as you will be vetting him.

What is best and most accurate way to determine what a house would rent for?

No worries about a seller sueing for specific performance.