What are the goals you want to achieve? 

How many houses would you need to replace your income or meet whatever goal you are trying to achieve?

You will find so many great resources here and will have no trouble finding a team of individuals who can help you achieve your goals.

Also putting together a general plan, what I’m trying to achieve.

This requirement is simply not achievable for some of my newer investment clientele, which is a tough cookie to swallow when a lot of these folks have big dreams and aspirations, and an ability to finance these at a slightly lower rate.

A normal 2 x 4 wall takes R13, which means you want to add another 5 to get to R19, you can achieve that by adding 1" foam on the outside ( R 5.6). you should break down your costs and find out what is best for you: add 2" framing and 2" extension jambs to windows( material and labor) + R19 -- leave existing 2x4 and spray foam-- install 1" foam on exterior,R13 interior, extend jambs and trim on exterior ( if vinyl siding that can easily be covered with aluminum). 

What are you trying to achieve?

I've purchased one-offs that have generated 100%+, and tapes of 75+ and struggling to achieve single digit returns overall.

It just seems like an awful lot of work raising capital and figuring out a lawful way to syndicate a deal just so you can achieve economies of scale.  

While you can buy a park at 80% occupancy and fill it over time, when you are at 35% occupancy you have to get to 80% before a lender will even look at it, and you are under the gun until you achieve that.The bottom line is BE VERY CAREFUL WITH THIS DEAL.