What is the best way to acquire the GBA Pokemon games at a decent price?

I recently got a DS Lite from a friend and found out you can play GBA games on it.

So I wanted to start the series with the Red and Blue/Green remakes and go on from there.

I found some copies for sale on Amazon and Ebay, but some of them looked pretty shady and others were described as "Recreations" of the original.

Do Recreations count as original games? As in, if I were to trade pokemon from that copy, would I get banned in some form when I transfer them all the way to the newer games?

Is there a trustworthy site/person where I could buy these games from?

(Sorry if this is not the right place to ask for this, but I really wanted to see if anyone knows any info about it.)