The Ivy Den Hutch (6') if my maths is right measures 6'x2'x2'. Total srface area 12' square so that gives them more than the recommended space for 2 GPs ( C&C cages recommend 7.5 sq min , 10.5 sq feet being recommended)
If you can get a run secueley attatched then they'll have the freedom and choice. But it would be difficult to move when they eat/dirty the grass in this area. (I've moved our run again and there's a rectangular patch that looks like locusts have been there.And left poohs)
Baby GPs will use a ramp, but when they are adults they tend to use them less-too much effort- my boars will go up their wide,shallow,carpeted ramp if they want to lard about on top of their haybox, but they are a bit meh.
The door catches look a bit flimsy, you'd be best to add some bolts.
And check how big the sleeping area is, this is where they'll spend most of their time.
Why not look on Amazon for cages (or Ebay-alot of new ones there or pre-used. The pre-used ones tend to be assembled and the vendors generally want the buyer to collect).
Mine live in my DC old playhouse. My DH put a big hay box in with a ramp to the 'lid' both are carpeted. Plenty of space for those all important little houses. We have a house on the lid of the haybox, a softbed under the ramp, a willow hedgehog house and a shallow tray lined with newspaper in a cardboard box. (For their littertray. They do pooh/pee in it. But also in the hay, in the hedgehog house and ,oh, anywhere their bottoms tough the floor)