V-6 Colorado - not much guts. With your equipment and to allow some growth I would not go over 6x12. I would not even consider an enclosed pulled by a Colorado, you'd better go open utility. I pull a 7x14 enclosed with my 4.7 V8 Dakota and it does alright, except in a strong headwind/high temperature day it struggles just a bit I have to take my time. Just an FYI.
7x14 Stealth SE Enclosed with 48" side ramp
08 Toro Z400 - 48" deck, 21HP Kaw
09 Exmark Turf Tracer HP 36"
21" Toro SR4 Super Recycler
Stihl KM90 Kombi w/ straight shaft trimmer & tiller heads
Husqvarna 125B Blower
Turfco XT5 Aerator
Turfco LS-22 Overseeder
I can do all things through Him who gives me strength.