Welcome to the forum.
We had a RP-180 and recently purchased a RP-192 which is similar floor plan with a bit more space.
Based on the truck specs you provided you should have no problems towing the 180 with your Colorado.
The price sounds reasonable if the 180 is in good condition. Right now there is a shortage of RV's, new and used, so it is a sellers market.
Wayne and Christine
2022 Sunseeker TS2380AFT On Order
2021.5 R-Pod RP-192
2020 Ford Expedition Platinum 4X4
3.5L EcoBoost 400HP with 480 lb.-ft. of Torque
9,200# Heavy Duty Tow Package with 1,524# Payload