I wish I could tell you anything at all about Amazon's packing practices being solid...
But I can't, it wouldn't be even a little white lie to say they were mildly OK at packing stuff.
Pet stores may be able to order stuff for you especially.. even if they don't normally stock it. for something a little more boutique I am sure that the folks selling should be more than capable of having it packaged to ship, just be sure to read reviews first.
Used tanks often come with a stand, top, filter, light (all quite possibly old) & a questionable heater. We here in the US often see good deals but also not great 1s too. Some sellers think because they paid $200+ for brand new 20- 55g stuff, it should be worth almost that much used. No! That's wrong. In large markets (like yours & mine) you can expect to pay $1/gal for tank & maybe some iffy stuff or $2/gal for better. Their neon gravel, tacky decorations & ancient food & meds are worth nothing! But high end rimless low iron tanks, LED lights, (or Kessils!), CO2 set up etc. cost a lot more, even used. But a "deal" only if you'll use them & they still work or you can get replacement parts ( easily & affordably).
Research a lot! I give bare tanks, plants, fish etc. away to club members, but hoard things like filters & even rocks & substrate I like, lol. Somebody's salt water set up CAN be used for fresh but will come with expensive things you won't use & the tank maybe etched. It's very not often worth it.
Resealing tanks is not very hard but is a bit intimidating, if I can do it (& I have many times) you can too! Be careful of "junk" particle board stands.
Plan to bleach everything! There's a good reason they're opting out of the hobby, likely a "plague" of some sort that killed all their fish.
Educate yourself before going into more tanks. Even "new" may not come with the good equipment you will want or need to replace in a year or 2.
Don't be in a hurry, we know you're excited with cory eggs & all!
Spring is often a good time for deals, be prepared when they come.
Yeah being excited is only part lol. But yea I have and am still reaching everything before I buy. There is a big sale at my LFS atm. But I am going to wait til the end of the month more than likely.
I do need a QT tank though. I am running a 2nd filter in my main tank (2weeks now)to get it cycled for a QT tank. Thanks for the advice and things to look into!