I have multiple properties and multiple income sources.

I use business credit cards and a heloc as well as cash and 401 funds but can always use more sources. 

Either of these could be source of funds to springboard an investment strategy.  

the key is in the valuations. 

Set up some keyword alerts for your areas of interest and it can help you stay on top of happenings there as well as help you meet some key players in those markets.

They will source the funds in your exchange account. 

I'm starting to look at working with Net Realty (wholesaler) in order to source deals in Dallas to rehab and sell OR rehab, refi, buy and hold. - My budget is about 250K for 1 house or less (not including rehab budget) - What would be a good area for a mix of appreciation and cash flow for a buy and hold? 

I've never bought through a wholesaler (but have been one a few times) so there are more ways to source properties like agents, FSBO, MLS, zillow, cl, driving for dollars, etc.

Online leads are definitely a source to look into. 

Your PM is so key with maximizing your ROI.I also transitioned to a new agent after my initial one.