Buy the biggest head size you can afford, horsepower is largely irrelevant for home processing unless you want to grind frozen items. A #32 with a big feed pan and good technique will grind 50lbs of sausage in under ten minutes. I personally really like procut grinders for the value commercially, but spending $1500 on a hobby that you’re also going to have to get a special 220v plug wired for isn’t worth it for the majority of people.

i would recommend a paper/fibrous type washer for that older style grinder, they heat up less than nylon. in general having a washer on that worm is going to better press the knife into the plate and give you a cleaner grinder.

Surg Horsepower doesn’t matter, period. The only situation where horsepower matters is if you want to grind fully frozen stuff, which you don’t because it’s going to mess up any grinder that walton’s sells. Get the biggest plate size grinder you can afford, it will take less time to grind and less time to prep because larger plate grinders have larger throats.

For a 25 lbs batch get literally anything, your run time isn’t going to be long enough to overheat a 115v motor. If you get into larger batches I would recommend getting the PROCUT products over a walton’s branded product. Procut is a lower level commercial brand and not a home use brand and their stuff is designed to not overheat during longer run times.

Lastly sometimes its better buy more expensive things with resale value instead of new items. A used hobart or biro or procut or berkel grinder has resale value if you get bored of the hobby or move on to bigger equipment, you can always resell a used commercial grinder for what you bought it for.