This probably isn’t going to help much but over the years I’ve gone through 20 plus mowers from most manufacturers, all have good points and bad. As for rollers or 4 wheels, it does depend on your clients but you will need both. My advice is to get a simple machine that doesn’t have to many bells and whistles and plastic parts as they all break and fall off. The vast majority of the time I use a Hayter 48 pro but I had to increase the engine rpm via the internal governor very trickle but well worth it, next is a toro 21inch recycler for a couple of larger areas where I can mulch as it’s so much quicker than boxing. Then I have a Honda 19inch 4 wheeler for when it’s a bit wet for the hayter. After that I have the lawnflight 18inch roller it’s nice but heavy but good back up for when I have to rebuild the hayter drive system a regular job! Other than that I have a couple of masports 21 inch rollers which work quite well but only on the flat absolutely useless if you have any slopes to run up. Overall I would go for a toro they work well in most conditions and fairly reliable