There are all kinds of choices for a 3pt backhoe to fit your 454. Taylor, Bradco, Woods, Nardi or Seagull, the Jinma backhoe etc. Biggest thing is to be sure to get a subframe for your backhoe to take the stress off the tractor. You may have to get one with the backhoe you buy and retro-fit it to your Kama.
Next is to consider the size ... the digging depth and reach. Your tractor is plenty big enough to get a minimum 8' one so you don't have to re-position yourself frequently. I have a Kama 554 with a Nardi (Seagull) 220 and I wish I got a little larger backhoe for it now. Your 454 is (about) he same as the 554 except the hp difference.