no clue what SLP is, but my standups have pipes from "Factory Pipe" They're both setup for low end stuff for jumping wakes and doing freestyle tricks. It's amazing how those pipes are engineered to fit in such a small place but still have giant expansion chambers and tuned water injection.
http://www.factorypipe.com/Products/Yamaha/yamaha.html I have the Factory B pipe limited on my ski with ported cylinders/cases/sleeves and Dan Lamey carbs. It has an R @ D intake manifold, dual 46mm carbs, freeride ported cylinders and all the handling mods you could ever want.
My other ski, the freestyle ski has this pipe
https://www.wamiltons.com/index.php?main_page=product_info&cPath=13&products_id=38
it has a single 44mm carb and stock cylinders.
What kind of 2 stroke oil do you run in your sleds? I use Royal Purple synthetic in my 2 stroke skis. My sit down 4 stroke ski is supercharged/intercooled and has a couple mods on it. Because it has a wet clutch setup it has to use regular dino oil.
I'm moving to Colorado in november and looking to get a snowmobile to start off riding with.