Haven't needed to replace the grate, so I regret I cannot help. Try contacting the company? Good luck!

  I think it's too small for one budgie.  I just got it as a back up cage in an emergency if I had to take my bird somewhere.  The cage is not very sturdy.  It's OK for short periods of time but I wouldn't make it my birds permanent home. My budgie has a 22 x20 cage that is his permanent home much bigger and sturdier. 

No, you are going to need a much bigger cage because they will need to be able to fly around and stretch their wings at times its only big enough for 2 birds, and that only if you are letting them out to fly around

Yes, the grate is removable.

I think it would be a little too small. It measures 22" tall, 16" wide and 11" deep. An article I saw online says they should have 24" tall, 18" wide and 24" deep.

It opens toward the right.

Yes, it is pretty to put together and disassemble. Three sides are connected and fold down, the 4th side and the top you have to attach but is is pretty easy. Note this is a travel cage, not a permanent cage. 

Hi NeedsInfo9, It is currently available in one color. Thanks,

This is not big enough to permanently house any bird, this is a nice spacious travel cage. 

No, this is not a good cage for any bird. It is way too small even for a single finch. You could purchase this cage as a travel cage that your birds would only be in for a couple hours or less. Also, the doors on this cage don't look like they include the door safety feature that keeps the doors shut until a human opens them. If you are looking to get an appropriately-sized cage for two finches, I recommend this cage: https://www.petco.com/shop/en/petcostore/product/prevue-hendryx-large-black-flight-bird-cage I have this cage and I use it for my finch & budgie (they live together) and there is plenty of room for them to fly around. It's a flight cage, which is what finches and budgies need to exercise. If you are looking for a more affordable option, I recommend this cage that you can use until you get the money to buy a bigger, better cage: https://www.petco.com/shop/en/petcostore/product/you-and-me-finch-rectangle-flight-cage Remember to use clips to "lock" any guillotine (sliding) doors so your little finches can't escape!