There is no suggested character. You just try your best and use the characters you fully-mastered. Good luck!
This achievement doesn't allow you to buy a paid respawn, but using a free respawn is fine. What you need is survival, so don't go and chase after Power cells when you are determined to get this. One mistake, and you will need to start all over again. Good luck to you if you want to attempt this achievement! Tip: Don't try to do super hard achievements to get this single achievement, it might make you mess up and you will have to restart all over again. Be very cautious! Good luck!