DAVE - Dad had a '57 LoBoy that he traded for a 154, just about the time I bought my 982. The deck on the 154 mowed really nice, think it was a 60 inch deck, but the tractor itself was under-powered, stuck with just the 3-speed, you always seemed to need a gear between the ones you had, and he spent $400 to have the local C/IH dealer rebuild the PTO clutch just before he sold it. He did the clutch R&R himself, the $400 was just parts & labor to rebuild it.
If I had a choice between an SGT & a 154/184 it would be an easy choice, the SGT is a much better mower, smaller & more nimble and attachments are much more available.
But between your two choices, I think the 154 w/creeper would be my pick. But the 184 does look better IMO. Local cemetary has a 184 hooked to a running gear with a 500 gal. water tank on it they use to water plants, trees, & bushes all summer. I keep waiting for it to get parked along the road with a for sale sign leaning against the frt tire.