Hi you cant go wrong with either andis or oster. I prefer my andis clippers. I've had these for about 10 yrs https://smile.amazon.com/Andis-Detac.../dp/B0018KVHJO
You'll also need blades, blade cleaner I like this https://smile.amazon.com/Andis-12750.../dp/B000LNB8HK AND https://smile.amazon.com/gp/product/B000MD57UI. The jar I use to clean dirty blades. the spray cools the blades down (and cleans them) Its recommended to only clip a clean dog but I dont see the point of washing & drying a bunch of hair I'm going to cut off. So, I have 2 sets of blades - one for dirty dogs and 1 for clean dogs.
How short are you going to keep him? You may need different blade lengths or combs.
other really "nice to haves" are a grooming table with noose though you can substitute any stable surface topped with a nonstick mat (like a yoga mat or entry way mat) and a dryer. You can use a human dryer on low but having a powerful 'dog dryer' helps blow out loose coat which cuts down on shedding and helps make the end look better.
if you get combs, the SS ones are COMPLETELY worth the extra $$. I have these https://smile.amazon.com/gp/product/B002RBWL1G. They work so much better than the slide on plastic ones I had that were always popping off or getting snagged.
dd1 10/05
dd2 11/09
and ... a mini poodle!