I know this is an old thread, but I had a couple of things I'd like to add for someone looking for a new grinder. My dad and I used his Hobart with a #32 head that he bought new in '69 for most of my life. He hasn't hunted deer now for about 5 years so it has been sittng idle for a while now. When I started butchering on my own, I started off with a cheap Chinese #12 I bought on ebay for $100. It worked fine for single grinding 1 deer. After spending 8 hours one night double grinding 2 deer, I order a Cabela's 1-1/2 hp commercial grinder the next day and couldn't be happier. With that said, I DO wish I had gone with a LEM because I think they would have better support. A few years after I bought mine, Cabela's changed there design to what is now their Carnivore line of commercial grinders. At that point I jumped on the opportunity to buy all the attachments I could for mine. Not long after that, LEM and Cabela's both introduced an ice pack for their grinder heads, but it didn't fit my older model. If I managed to break something on my grinder, I'm not convinced that I'd be able to get a replacement part to fit it. With that said, if something breaks on it, it will be because I did something stupid.
As far as size, I always tell people to get something that's equivalent to a #32 because its big enough to fit your hand into when you're cleaning it up afterwards. The thing I hated most about that cheap #12 was trying to clean it up afterwards.
Other tips I've picked up:
I put all my grinder parts in the deep freezer for a few hours before grinding meat.
I coat everything with either olive oil or grapeseed oil (both are available in aerosol form at walmart) before putting it in the freezer. Things flow though the grinder MUCH better this way, and cleanup is a LOT easier. I used LEM Silicone spray for several years, and that helped a lot. I ran out of that last year mid season and grabbed a can of PAM Olive Oil because it was handy. It worked MUCH better than the silicone, especially on the 2nd grind.
I use a foot pedal to only have the grinder running while I'm feeding it meat. NEVER trust that the foot pedal will prevent it from turning on because its VERY easy to accidentally activate it. You don't need the expensive foot pedal offered by Cabela's or LEM. Any foot switch from Amazon or Ebay will work so long as its rated for at least 15 amps (that's all most wall outlets are rated for anyway).
Meat doesn't freeze until about 27 deg F (pork is a little lower). I keep mine in a modified freezer set at 27 to 28 deg prior to grinding it. If I let it set all day, or over night at 27, part of it will be frozen when I get it out but if I put it in the fridge for an hour or so it will thaw enough to start working with it, and it grinds GREAT.
I use Sterilite 12qt containers to put my meat into and to grind into. They old about 17 lbs of meat, they are cheap, they clean up pretty easy, they stack, and they fit nicely in the fridge.
Lastly, if you double grind and the 2nd grind just doesn't want to feed for some reason despite the meat being cold enough, try taking out the plate and knife and re-installing them. Sometimes, I'll get a piece of silver skin in between them right off the bat, and its a fight to get it to feed. Once I clean the plate and knife off and reassemble, it always runs great from that point on. This only ever happens at the very start of the 2nd grind for me (like right off the bat), and I haven't had it happen since I started using the olive oil or grapeseed oil.
Oh, and with a good #32 or equivalent head, the grinder will take the meat almost as fast as you can feed it on the first grind. If its warm outside, I'll put the meat back in the cooler at 27 deg for an hour or two (along with the grinder head) before doing the 2nd grind. I butcher in my mudroom which is not climate controlled. If its down in the 20s outside, I can skip putting stuff back in the cooler. I have a spare fridge in the mudroom and all the containers of meat go in there while waiting to be ground, or after grinding waiting to go back in the 27 deg cooler.