2012 Nissan Titan, Considering Aftermarket HU and Speakers

I have a blown speaker. I was thinking about replacing it but having a little trouble finding a 2ohm 20w 5x7" (I think thats the size?). So I'm thinking my stock wiring is set up for 2ohm? Everything for sale is in 4ohm. Would it be preferable to take this time to ugprade the Head unit along with all speakers (even wiring impedence?)? should I just throw a 4ohm speaker in the 2ohms place? 20w seems low for this one channel. Please inform me since I've forgotten a lot. Thanks!

unsure if its smart key or regular key. I'm guessing regular.

You can put a 4 ohm speaker in it's place. You may notice a slight decrease in volume. Slight. A lot of the 2 ohm aftermarket speakers are very inefficient and will give the same result.   I think that vehicle has 6 x 9 drivers in the front doors and 6-1/2 in the rear doors.

Would you think its at all worth it to upgrade the system? Headunit that can put out a little more(200w?) and speakers that can handle a little more (50w)

What 200 watt headunit are you considering? It is probably an 18 watt per channel unit. There are now a few that will do actually 45 watts per channel. A new headunit will give you better sound, but not going to be any louder. Unless you get one of the few that do the 45 watts per channel.

thank you for all your help!