Whats a good all around setup

What do you mean by ag products because to me that’s grains hay fertilizer lime maybe some dirt or rock. I’m guessing you have something else in mind based on the trailer you mentioned

 

I’ve pulled older mg trail kings, I’m not sure if you can get a well quite that long as a tri. Ours where tandoms with a pin on third on common air. Be ready to build some ramps if equipment doesn’t fit in the well, and smaller stuff has a hard time climbing up the front but I think that might be a limitation of all rgn’s. We had 1’ separated crossmembers w/swing outs. Make sure the one you get has the chain slot cutouts or you going to have a hard time finding a good way to tie things down or your going to ruin a lot of chain. the slide out trailers are a fare bit heavier.

Overall they have been good trailers.
Movealls of the same size and build but with aluminum slide outs are heavy. (I can’t remember by how much but I think 4k ish. They were all right but a bit more of a fight to split in bad weather.

On the trail kings make sure when loading/unloading you push the nob for the neck back in. If for some reason you fall off it’s either never going to work right again or your going to have a bad day fixing it right. You will have to disable the auto catch that holds it out when disconnected.

 

from what I can see the slide outs are better because they can be used to cradle a tire and effectively lower your overall height.
I have a trail king hdg??? 3 axle that’s 53’ and I have a 26’ well. You can probably get a 28’ well with the same trailer and a shorter neck. My deck is 18” thick and my deck height is 26” at the highest part of the crown. I mostly move construction equipment and some industrial stuff. Most farm equipment is to tall on my trailer.
If I were looking for a trailer to haul farm equipment I would probably be looking at a 35-40ton with the lowest deck height possible. I think a spread axle would be better. If you’re trying to avoid overweight permits a spread will carry the same weight as a tri because of the weight savings of one less axle (in Illinois) If you’re going to be running permits you will only easily be able to permit to 100k in Illinois. I think that would be ok for most farm equipment.

 

Slide outs are a convenience. It is likely still possible that if you get swing outs to get strap winches for the main deck, it adds some freight choices if you have em. (We did, I might have used em once a year, straps w/ chain end could usually do the same thing if needed.) It entirely depends on what you want to haul. Farm tractors -shouldn’t need need em unless a wide stance row crop.
Track machines -same thing
Combines -wheels on, only pull outs
Sprayers -again only pull outs (some lighter units may work on swings but most if not all distance between the tires is < 8’6”.
Rock truck/front loader you will likely be fine without any extension, size depending

Is it worth it, do you need 600hp? 350 will get you there. Will it limit your freight options, yes either way. You could get one that doesn’t have ‘em. I don’t know your market or your business plans

if you have less than a third of a tire or track on your fixed deck you should use slides. Or you need to build steel sections instead of boards for the swing outs

 

Aluminum reefer flooring planks are lighter and are plenty strong enough in most cases.
Check with local heavy towing companies concerning where write-off trailers are parted out to find them.