Cage size help (NIC+Dog Crate)

So I will be getting a 8-week old Holland Lop, right now I am only planning on only having one bunny, but I may add another down the line. My idea is to use an old dog crate (I think this is it http://www.petco.com/product/13372/Petco-Premium-2-Door-Dog-Crates.aspx dimensions are 36" L X 23" W X 25" H) I was wanting to add another level in it like this but I don't know if it's tall enough. Then in addition I was going to leave the front door of it open to lead directly out into a NIC cage attachment. I am not sure how big I am going to try to do 1.5-2 grids wide (depending on space restrictions) and 4 long and 2 high. Is this enough space for one holland lop? He will spend a good amount of the day due to the fact that I am in school and my dad works. And if it was 2 grids high would I need a top? or should he be able to stay inside? Any help would be great

I use a dog crate of the same dimensions for my 8week old GermanxSatin angora baby, she is already larger than your's will be. I'd thought about putting a platform like the one in your picture, but she will be too big for it soon, so she just gets a lot of out time. As for the top, I had intended to leave it off until she decided it was time to be out and cleared the side like it was nothing- so now the top is on.

I will post a picture in the morning if that will help.

That sounds like it should be enough space. Whether or not you need a top, or higher pen, really depends on how athletic your bun is. If you don't want to use NIC grids for the pen fencing, you could get an xpen instead. I would say to go with one that is at least 30" high.