Sadly you guys talking to Indonesian here that all he knows is go to the shop, get a modded ps2, then go and play it.
Foxi4 explain everything you need to know about PS2 Modding, I prefer using Modified memory card, since you don't have to go breaking your ps2 and soldering stuff... And I don't think MagicSwap is a good solution here... Well I'm talking about Slim of course.

Plus mod chip breaks your ps2 easily, your optic read more harder than usual, and it probably affect your power supply too (just like what happen to my ps2)

HDD is a good solution, ext HDD is a bad solution.