I agree with sd455dan on the
L5450 sounding odd with a new clutch after only 226 hours.
I'd be torn between the DK50SE and the Kubota
L4240. The Kioti is a little more tractor, but the
L4240 has the fancy transmission that would be handy. Ask whether the
L4240 has any rear remotes on it. They will be expensive to add (probably around $1,000). The DK50SE had one set of remotes standard and, hopefully, whoever bought it had another set or two installed. I've got 2 sets on mine and wish I had 3.
I'd reject the others because of the shuttle shift transmission. Also, I thought the TYM used a Perkins diesel engine, not a Kubota engine, but I could be wrong. And there's nothing wrong with a Perkins diesel, which are great engines.