Here are a couple to start with: I simply got these off the web so I have no idea how reputable they are but try them and see Bankers Title Corporation Parque Centro 1500 San Juan, PR 00918 787 * 753 * 0339 Efrain Tirado Appraisal Group P S C 1431 Avenue Ponce De Leon 801 San Juan, PR 00907 Estudios De Titulo Ana Echevarria Investigacion 102 Torres San Crst 204 Ponce, PR 00780 Finca Galateo Limited Partnership 207 Calle Tetuan San Juan, PR 00901 Garcia Andres Rivera 555 Prira Leal Street Apartment 201 San Juan, PR 00923 787   531-1179 Ocean Park L P 207 Calle Tetuan San Juan, PR 00901 San Juan Abstract Seguro Titulos 259 Calle Chile San Juan, PR 00917 William Negron Quinones 402 Calle 2 San Juan, PR 00923

@Juan BravoCheck out the people @Dennis Rodriguez mentions.If a bank won't be involved, make sure you do a title search ("Estudio de Titulo"), make sure property taxes are paid and I would get Title Insurance (just to be safe and it's cheap).I don't know about any specific problems/issues/concerns with the owner financing part.

To purchase a property in the dominican republic you only need 3 docs certified:1- certified of title ( Titulo y deslinde )2- certified of lien (Cargas y gravamen )3- certified of taxes ( IPI )if you get those 3 things you can get the information on the web portal of those institutions and get the information if those are original and are right and if are right you can buy without problems another way you can get a mortgage is with the bank and the bank makes everything for you.I do investment in DR I live in Punta cana if you need more information pls let me know 

@Richard Alvarez I am currently building a portfolio in the country and would like to ask you a few questions.For the 28 units do you have titulo deslinde for each apartment, financials, copies of liability insurance, pictures etc.Can you inbox me where you have land and how many m2 or tareas for each land.Do you have titulo deslinde for all of the land and locations?

When purchasing a property all properties should have "certificado de titulo." this is a form of guarantee the property is your property. 

That being said, to me it sounds like the initial $670 fee you were charged was the " Initial Deposit" Here in PR ( and many places in the states as well) lenders charge a fee once you are under contract on a property to cover the initial expenses such as the Appraisal, Plot Plan ( in PR these are mini-surveys on single and multi-family homes), and the Estudio de Titulo ( title search). 

Esto basicamente cambia el titulo de la casa a otro persona o entidad.