The weight argument isn't a big issue as the wheels are unsprung weight so you aren't going to increase your cargo carrying capacity at all. By the same token, you aren't going to decrease the overall weight of the trailer by much either so your TV's gas mileage isn't going to change any detectable amount.
It boils down to what you prefer. I like the looks of aluminum wheels over the steel counterpart but I'm not going to spend $400+ just for some wheels that look nice.
If you like the looks of the Al wheels then go for it.
2006 23B Hybrid with 10k round bar WDH
2011 F150 4x4 SCREW Ecoboost, Max Tow, Integrated TBC, 3.73 LS axle, Firestone Ride Rite airbags.