I don't think that your dealer is right. The big brand names do make "estate" series implements that are designed for subcuts, however there are many members on
TBN that use full CAT1 with their subcuts. I have a Kubota bx1500 and use a full size CAT1 rake.
What brand/model rake is it? Also, if you are able to fab up a set of wheels, you could save a bunch of cash.