Hi CKL,
How many books on average would you bind a month, will you be folding the sections first, how much room have you got for the binder?
If you are only doing small runs then the Horizon BQ270 is a good solution, it will only do about 300 books an hour maximum, if you are doing bigger runs then the horizon BQ440 is a faster machine, doing about 1200 an hour, if you are doing very large volumes and have a lot of room then you would want a hoppper fed perfect/burst binder which are a lot quicker but you do need a lot of room and a few operartors.
Another thing is trimming the books after they have been bound, if you are buying a smaller binder you can pick up old three way trimmers, dont buy new ones they are far too overpriced, or, you can just use your guillotine, make sure you get a sponge magnet to put on the clamp to stop the spines cracking.
As far as problems go, there arent many with the horizon type perfect binders I have ever seen, you just need to set them up correctly and away they go.