There are only 2 options for those.

Another great option is the BRRRR method (Buy, Rehab, Rent, Refinance, Repeat), where you buy a fixer-upper, renovate it, rent it out, and refinance to pull your cash back for the next deal, and this is a good route because most private lenders can go higher LTV than on a rental loan! 

I have been told to stay away from lease options in Texas.

Since you want to aggressively invest in the near future, you will need cash and the 30 year option is the right one for you.

@Kwanza Price - Syndications are a great options and even some QOZs. 

I do single family "off market" that I take over with owner financing, subject to, wraps and lease options.

I recommend that you find a trusted or recommended Mortgage Loan Originator (MLO), who can give you options for property-based loans (mostly investment loans) and they don't use your taxes but the P&L of the property.

If you are skilled in each of the areas above, and you have enough in reserves to cover the costs of when things do not go as planned, then you can likely attract money from private money lenders who want to get a return on their money and they see lending to you as a low risk way of earning a better return than in the other passive investing options they have. 

Happy to chat through some options.

Your best option would be to refinance your loan (if any) and get a construction loan for the improvements.