hello, i get into this situation alot with my ferrerts, so i just go down to my local game dealer where they have some lovely just shot rabbits spare. they have no head and no guts but fur and skin so that may be worth trying out.
now about the run just make a smaller reclangular sourt of shaped run but not to small u will whant it about 6x4ft or a little but smaller if u like. but make sure u put things in their to keep them ocupied cause they like to run about and play with stuff so just cuck a old rope and hang it up then they will get some more exersize on that.
well hope this helps
har