the best advice I can give when it come to getting into the big truck/equipment league is "Overkill Is Underrated" that is the motto I follow with my businesses and it works out great. when I first started doing tree work I had bought an 8" chipper and thought this will be good for now, I could have afforded the bigger chipper but I settled for what I thought I needed. that was ok but I outgrew it overnight. when it came time for an upgrade and expansion I followed the new motto, we said we need a 12" chipper with a 4000lb winch so I bought an 18" chipper with an 8000lb winch and we constantly max the 18" chipper out but it was good to buy bigger.
with that said if you decide you need the CTL and think a T190 will work buy a T300 or T320. and when you decide to get a dump truck and think a single axle 25900# GVWR truck will work (I can promise it wont I know form experience) buy full CDL truck. I can tell you when it comes to a single axle dump if you buy anything under 36K gross you'll regret it.
plus if you decide to get a dump truck buy a hook truck. if you want some reasons why let me know and ill write a book for you.