You need representation in several ways.
First a buyer's agent. If the property is listed in the MLS then the buyer's agent can be paid according to what the Listing broker has agree to split with the Buyer's agent as per the MLS. Your interest will be represented and you do not have to agree to the pay the Buyer's agent any additional commissions for their work.
Second, If you can find a buyer's agent who has construction, rehab, remodel experience, that is even better.
Third, If you can find buyer's agent who has investment property experience, that is even better.
Fourth, be prepared to pay for additional qualified inspectors/contractors to evaluate the property. A typical Home inspection company for a property as you describe is only a start, but should probably not be your only opinion as to the condition of the property.
Last, if you are able to use 203K financing, it would be helpful to have people who know how to review contractor bids and make sure you are paying a fair price for the work and that all the work necessary is covered.
On another note, the listing agent and the Seller are under no obligation to give title reports or any due diligence information prior to you showing your willingness to buy the property. i.e. make a written offer with some earnest money. If you make a written offer, there will be a contingency period for you to do your due diligence and you will have the opportunity to back out if you need to and not loose your deposit.
What most buyers are never coached on is that, if you are serious about buying a property, plan on having up to $1200 of non-refundable risk money. A typical home inspection runs $350 to $450. An appraisal runs approximately $400-$500. If you need to bring other contractors out, there can be a service call with HVAC, Plumbing/sewer inspection or an inspection fee from a foundation contractor for example. You might pay for termite or mold inspections. The point of the non refundable risk money is so you can assure yourself that you are comfortable buying the property in it's present condition and any foreseeable conditions that may come up as a result of your due diligence.
I have references for foundation specialists, Licensed contractors. I have construction experience both in residential and commercial - if you have any questions please call (805) 432-7705
CA DRE #01228452
P.S. I have done pretty extensive remodels on a few homes I have owned and I am pretty tight with the money and know where to pick up the savings on these projects.