Chris-
One thing you have to keep in mind when wholesaling a fix/sell to an investor is that he/she has to close twice on the house, so that eats into the 'profit'. So its not quite as simple and saying roughly: purchase 100k, rehab 25k, sales price 165k = profit of 40k! It irks me sometimes when wholesalers try to have me dreaming that is what I will make. The wholesaler undoubtedly will have the investor pay for all closing costs, then holding costs, extra rehab costs (always happens), then the REI's buyer will have the investor pay for closing costs. $40k will get eaten up quite a bit.
So in the pitch to your buyers, you might have some other costs shown in there, so that the 1st time buyer won't lose his/her shirt but will come back for more because your figures were very accurate.
In respect to a buyer looking for rentals, I agree w/ Stefan and the 50% rule, but it doesn't take into account what an investor has in the property. I have purchased props, rehabbed them, cash out refi the property and put extra money in my pocket. In essence I was paid to own the house and it still cashflowed. It wasn't 50%, but what is the ROI when you have zero dollars in a rental? I personally like to be in a rental for 70% ARV or less after I rehab it.
Good luck!! There are probably many buyers from Dallas on here who would be interested.
Eric