Which retainer is best for lower teeth, metal or clear?

I just finished my treatment for 3 and a half years wearing braces and now i was advised to have clear retainers but for the first week i feel sick and tired of putting them on and off every time i have to put something in my mouth what should i do? Do u recommend the back metal retainer for the lower teeth I have seen that there is a metal wire from the inside right behind the the lower front teeth