Couple of things: You probably won't be buying the newest and latest equipment. So, sickle mower (1-armed bandit), bar rake used, and an old auction candidate baler, no kicker or thrower and no wagons behind. My mower is a haybine (Hay + combine). Not only does it cut the hay but it 'conditions' it by passing it through a pair of crusher rolls. It has a reel out front to comb the approaching hay uniformly into the cutter. It then also has the ability to windrow the hay, good for several reasons: The ground will dry in each side of the windrow, which then can be side raked and flipped to get faster drying time. If you have GREAT weather, you can bale this windrow without the need to rake it. This mower needs a hydraulic supply, though, for header lift and the tongue swing. Tongue swing is not just for getting thru 10' gates, it allows you to differentially alter the cutting path to avoid fence posts, stones, whatever. The header lift is mandatory not just for turning around but to have the cutter self clean if it's picked up dirt or clumps. Raking, well its bar or wheel, or turnstyle/spinner. I have a bar rake and tow it on a dolly, I can rake with my golf cart. I also have a Kuhn tedder/rake combo. Throw a lever and adjust the wheels I can rake or fluff it. PITA to convert for several reasons, so I use it to fluff and the bar rake to windrow.
Baler is from the 50's JD 14T, a very popular baler these days for very small operators. Easy to fix, parts available because the common replaceables work on the new small square balers. Plastic twine works for me. The only issue I had was related to the driveline hookup. The short shaft from the braced driveshaft to the tractor MUST be centered over the hitch pin. This is because when you turn a sharp corner, the U-joints must be kept in phase. If the hitch pin is not in the center, the U-joint angles will be unequal and this will shudder & shake the crap out of the machine. I had to add a hole in my drawbar to get this to work.
Fact is, I'm working with a gal (who is on this forum), to get a NH bar rake, NH mower(s) (a 9-1/2' NH1465 and a 7' NH472) and a JD baler going right now. She has horses and dreams about providing her own horse food supply. She has a JD 4300 (30horse?) and it handles all the equipment just fine. Rear tires are loaded. Hitch is tight so no bucking. And she has 5 acres to do, just like yourself.
Now, the newer hay making machines are for real hay farms. thousands of bales. Takes time, maybe air conditioning, 3 or more hydraulic circuits, high weight for traction, big brakes, highway speeds, disc cutters and discbines, and all this takes much more power. Even big radiators. And these machines have many other heavy tasks. Snow plowing a driveway isn't one of them. Therefore, dealers go for the conservative HP estimates because you also get the weight and the features of a 65 hp tractor. They even look better IMHO. No teeny weeny tires, self leveling loader, battleship cab, lottsa levers, stereo, refrigerator, barbecue, keggerator, etc...
BTW: I have videos of my mowing and baling with my Deere in 2nd range. I could go faster but the fields are too bumpy.