Simple answer: It's not a clone and supports all firmwares to date. Team updates firmware if it gets blocked (like supercard). You never need to buy a new card (The original one the OP linked only gets supported for a year and then they make a new cart and never update the old one.)
Suuuuuuuuure:

They only released 12 versions
without even giving them different labels so you had no idea what version you got before receiving it. And of course you had to buy new card if previous one was blocked.
Now for real info:
1) There is no original R4i cards, all of them are clones. R4i Gold 3DS just has official wood support, but other manufacturers have hacked that version to work on their cards a very long time ago.
2) R4 SDHC Dual-Core 2015 will work just fine, it won't need any additional support since DS games are not released anymore.
3) You will never have to update it, DS flashcards are not blocked anymore.
4) Don't bother with DSTWO unless you want crappy snes/gba emulators.
5) The only real difference between R4i Gold and R4i Dual-Core is RTS support on Gold but its not very good.
EDIT: 5 depends on Dual-Core version, there are 2 types of them...one uses Wood menu and other uses TTmenu which will have RTS and it'll be much better than Gold version of RTS.