Fabric play pen?

I'm thinking of getting another rabbit for Hoy after Christmas, hopefully a mini lop. Will this play pen be okay for them to stay in? They're going to be kept indoors but I'm not sure whether this is big enough or whether it is a good idea to have a fabric pen for them.

Also I would need to know which one to get. The small one (37cmW x 37cmH or 14.5"W x 14.5"H ) or the medium one (61cmW x 61cmH or 24"W x 24"H )

http://cgi.ebay.co.uk/GREEN-MEDIUM-...QQptZUK_Pet_Supplies_Dogs?hash=item45efb47b71

Advice needed!

I think you forgot the link

I would imagine it would get chewed, and they might then get their head caught in a hole (if it became large enough) or escape.