Most of the major companies will require you to have many thousands worth of their stock on your floor.
Spartan are new kids on the block so I would be looking there.
Start with the one brand and add on as you go to suit what your customers ask for.
Small companies will treat you a lot better than big companies and having a brand that is not stocked by glass fronts will make your life a lot easier.
Stens, Oregon, Prime Line, Rotary and who ever else does after market parts.
None of them will demand you hold $10,000 of their goods as min holding stock so you can fill your showroom with all of the add ons for very little outlay
Walking into a shop with posters all over the wall does not make customer feel confident.
Walking into a shop with 300 belts hanging on one wall , 50 blades on another wall, fuel cans, trimmer line chains and bars on another makes it look like you are solid and know what your are talking about.