When I bought my DX55 (basically the same as your TC55), my dealer gave me 2 options for weights. One was from CNH and the other was an aftermarket brand that was somewhat less expensive. He recommended the off brand to save the money but did warn that they don't always fit so well. I opted for the CNH so I wouldn't have to mess with grinding them to fit if needed. I was getting a good deal on them either way since I was buying them along with the tractor though. If I was buying them now I would opt for the off-brand but still from my dealer. I'd check with your NH or CIH dealers there to see what off-brands they can order for your wheel size and compare prices.
By the way, I like the added weight from 2 sets, without the extra weight of filled tires. But they do not give nearly as much stability as filled tires. Depending on your needs, keep that in mind.