Since then the company which provided the solo 401k was acquired, rules changed so that now (in 2023) what companies offer this option?

First,and before anything else, you must decide are you wanting to run a business or a side gig that provides a few homes to vacation to. 

Many lenders typically require a minimum loan amount of $75,000, allowing you to access up to 75-80% of the property's value, provided that the DSCR ratios meet the lender's requirements. 

We use everything we can do to provide more exposure and potentially find a quality tenant, including MLS.

Could you provide granularity on costs segregated and potential assets?  

You'd probably want to search locally for this - if in West Virginia, first search would be local banks/credit unions or SBA loan providers

Of course, this assumes you're keeping track of everything religiously, as it would be hard to reconcile such records and ensure completeness.Otherwise, look into hiring a bookkeeper/accountant/CPA who can provide this as a service for you and can help advise you proactively, so you can prevent issues rather than remedying them after the fact.

AirDNA can provide some insights on data in the market you're planning to work in.

Please share the listing so we can provide better feedback.

Additionally, holding a real estate license as an investor not only saves on commissions but also provides valuable access to tools like the MLS, enhancing your capabilities as a wholesaler.Feel free to share where you are located—there might be exciting opportunities waiting for you!