New bun help!

Hi guys!
So I'm new to this forum and I recently rescued a beautiful male continental giant. I didn't rescue from a shelter so this wasn't planned, basically a guy was keeping him in a 4 foot hutch and it was only a foot high and there wasn't even a run attached, he was just kept like that. I couldn't leave him there so I took him in without hesitation and here I am! So because I was unprepared, I went straight out and bought a hutch with attached run (still small but I thought it would do the job until I got a bigger one). In the end, it ended up being so small he couldn't even turn around in the hutch (he's a really big bun). So I quickly searched the internet and found a 3 foot by 4 foot run for sale and attached a cheap small dog kennel to the outside. This is what he is in now but it is still too small (although a lot better than the run). Anyway now I have done my research and learnt what I need to know about keeping a bun, I searched for a cage large enough for him (I wanted as big as possible so that when he is neutered, I can get him a girlfriend). I found a huge run for sale which is 10 feet by 7 feet and 7 feet high and I plan to buy some wood and add some levels in too. I was just wondering if you think this is big enough for him and in the future, another bunny or not before I go out and buy it. Also is it nescessary to have a hutch or can I use wooden dog kennels? I just don't see the point in having something that closes when he can have full access to his run when he wants to (predator and weather proofed of course).
This run can also be expanded so when I move and have a bigger garden, I can make it as big as I want.
Oh and I tried keeping him indoors but he is such a frightened boy at the moment that he was getting too stressed out being round people and the other pets so I had to move him outside for his own sake, I will be bringing him indoors when he is comfortable around people. I don't think he has ever had human contact to be honest.
Sorry this is a very long post but I wanted to make sure I said everything to help you understand the situation.
Thanks!

I should also mention that I want something tall that I can easily get into and sit inside with bun to get him used to me but also doesn't feel cornered which is why I chose this one.

I have a question, that screen shot looked beautiful why can't you buy the material and build it yourself? We built our 3 rabbits a 10 foot by 10 foot outdoor pin to be in all summer long so they could tunel in the dirt and eat grass like a wild rabbit. But winter is here and I have moved them inside to protect them during the winter. Trying to make them indoor pins as we speak. My husband will probably end up building one.

Hey!
I thought about building one but I'm absolutely TERRIBLE at building anything or doing any sort of DIY (I even need to ask people to change my lightbulbs for me hahaha) and I don't want to do it wrong or badly and end up with him getting hurt or escaping. It would end up taking me a long time to get it built and I don't think it's fair him being in that tiny run for much longer. This run is actually only £160 too so if it is big enough, I always have options of attempting to build or getting someone to help me build in future

Just remember that regardless of what you buy you will want to install something so he cant dig out and nobody else can dig in. That may mean laying wire mesh down and covering over with dirt and grass and putting the run on top of that, or digging down your fence panels.

As Watermelon mentioned above that is probably a good idea to burry wire under the entire pen. We didn't do that for our rabbit pen, but they love digging tunnel and holes in the dirt. They had one that all three rabbits could fit in at the same time. But they did end up escaping at the end of summer, but we caught them. We have had to catch them many times but they have always been safe. I live in a small town and my backyard is far from the road so they stay out in the back eating grass usually. Until I try to catch them..lol

I transformed a 6x8 shed into a hutch for my 2 buns (mini lop and a lionhead Cross nethie) with a 6x3x3 run attached to it

That's awesome!!!!

As for digging, my run is on slabs so they can't dig, but they have got a sand box in the shed they do like to have a dig in.

Sorry for the late reply guys. I have been really busy over Christmas and New year. I ended up getting him the metal run and a new girlfriend (who turned out to be a male and attacked him). The run is HUGE and it makes my giant boy look tiny in it! I have him a wooden, insulated dog kennel in there for shelter because he uses it all the time and I don't like locking him up in a hutch because of his size. I should also mention that he is on concrete slabs so there was no need for underwire
Your shed looks beautiful by the way!!!!