I like the way this started out as a consideration of a CK30 or
L3400, and now we are all the up to the DK40! While obviously the DK40 is a beast of tractor at a great value price, does the OP really need that? You could take the price difference, or evan portion of that, and buy some extra goodies for a CK or the
L3400. If you don't need the weight, HP, and the super high loader capacity of the DK40, wouldn't this make more sense?
The smaller tractor is easier to manuever. Attachments will be smaller and cheaper too. You'll need at least a 3/4 ton truck to tow the DK40 too. BTW, all of kiotis will require an 18 ft, 10K trailer to haul.
Me, if I didn't need the bigger tractor would consider these goodies added to a CK35 (the CK35 gives you the most hp available on the CK chassis):
2 sets of rear remotes (should get one with the backhoe anyway)
top link and side arm hydraulic cylinders
filled tires (a must, I think for loader work)
skidplate to protect filters
toothbar for the FEL bucket
big foot outrigger pads
2 hooks and a tow hitch receiver welded on the bucket
1 hook on backhoe bucket
backhoe thumb
sunshade
snowblower
grapple
pallet forks
posthole digger
log splitter
rake
boxblade
backblade
chipper/shredder
bushhog
finish mower
Obviously you couldn't get all this for $25K. But, you could pick what you need/want most. The point is that sometimes it's better to spend the money on attachments and accessories rather than pure HP/lift. After all, tractors are only useful with the proper attachments. Just something to think about.