New here, first post and ill try not to confuse everyone!
I need some advice ( and will still consult my accountant ) on a new venture.

I have an established landscape design/ build company - 20 years old. I'm a sole proprietor.
Another friend has a grading company - also 20 years old. He's incorporated.
We just started a separate landscape supply and design company together. It's a retail establishment so we formed an LLC with a separate name.
Now, he has more equipment, product ( bulk mulches, topsoils, gravels, etc..) and employees than I do. We split the bills down the middle for the new store.

Should I incorporate ( S-corp ) for my established company? His accountant seems to be telling him to actually make another company since most , but not all, of his bulk landscape materials were already on another site before we started this new retail venture. But, much of that material will be sold at the store.
I want to make sure we keep our established businesses separate from a liability standpoint and take advantage of all the tax breaks we can.

I'll be selling outdoor living merchandise ( grills, fountains, smokers, furniture, etc.) but will channel any design and installs through my first company.

Hope this isn't too confusing. I know there's probably few ways to do it but wanted some others input.
Thanks,
Dave