Steve, there are hundreds of aftermarket suppliers and one of the best ways to find discussions about them is to do a search of the forums for your desired accessory or to look in the accessories section of TBN. For example, if you look for toothbar you will find many aftermarket suppliers.
For the two specific items you mentioned, grill guard and FEL cutter bar, I would feel I wasn't doing you a favor if I suggested anyone other than your New Holland dealer. The perfectly styled, fold-down grill guard from New Holland is about $200 and the FEL cutter bar is about $170. They will fit your tractor perfectly and are excellent products. I know because I own both of them. ...my two cents.