I have a Burnham Alpine boiler. With that unit all the weight is held by the top bracket and the bottom one just holds it to the wall. I drilled two holes through my foundation to the outside, got two threaded SS rods and bolted the bracket to the wall. I used a piece of kindorf on the outside as a brace to spread the load. On the bottom I used two compression anchors that I got from Grainger.
It could be beneficial to just build a dummy wood wall if you have a lot of piping and pumps to mount, I used kindorf on the wall and mounted all my close boiler piping to that. However, the idea did cross my mind to build a wall about 3 feet from the foundation wall so that I could run piping behind it so everything looked neater in front.