Your reputable contractors more than likely will have some type of legal contract to sign once the work is agreed upon.  

The Domini 400 index measures large-cap stocks with reputations for ethical business practices.

It could also tarnish your reputation as a wholesaler.I would not recommend spending any time on the MLS looking for hidden gems you could wholesale.

NOW, ( My personal opinion) In my advantage (I'm a license realtor, 90% of my business is on the investment side)  the only thing it really helps me I've seen is that only provide legitimacy, reputation reliability , professionalism and some authority, IN front of other investors or partners or sellers (JUST for the fact I have a license, Not the knowledge gain on  the test ...) 

EXP has a great reputation for training and is doing a lot of really good things out there in the market.However, it's hard to say on the aggregate level that EXP is better than Coldwell Banker, for example.

If you're looking to do this for the long haul, your reputation matters.Here's an alternative thought: Have you considered an ADU?

Does anyone know any reputable commercial real estate lenders?

I’ve been invested in an array of multifamily and MHP private syndications as an LP for 2 years now, a convenient way to invest in real estate passively while I work overseas, leveraging the experience of a reputable sponsor/s.

To be honest, if this deal is real and you have good comps for your ARV and firm bid from a reputable contractor, you have a great deal here.  

Are there any other reputable options that I should be looking into.