I think you will find that the local bar does not have the recovery points ( screw in eyes ) which depending on how you use your vehicle, may be a significant loss. Remember the factory eyes are recovery rated anchor points which you can "snatch" recover with.
Yes they are dearer, but just make sure the cheaper item does not reduce your functionality. You may find you need it in the future..
If you intend on pulling a trailer with lights you will need to get the trailer module and wiring that goes from inside the right rear interior panel down to the hitch. ECS Tuning sells the wiring kit for the T2 for around $600, not sure how much it is for the T3.
If you only intend to use a bike rack then you won't need the wiring.
Yeah as above, check what wiring is included for dealer fit. You should've negotiated at point of sale - hammered my dealer and got bar, wiring redarc battery isolator and tow pro brake controller for about $1500
Watch issues for warranty, I looked at aftermarket and got quotes from $1K to $1,500 for Hayman Reece. Then I heard of the wiring issues and the loss of warranty, means if something goes wrong with the electrics you have to go the tow bar fitter the dealer won't cover it. My dealer has had 2 Treg's with aftermarket bars and burnt wiring in last 6 months.
Go with the factory unit. It's more money, but it's also a plug & play install. When I had a 2013, I used the factory unit and it worked flawlessly. When I had a trailed hooked up, the factory tow module switched the programming in the transmission and I never had any issues. Now I have a 2010 with an aftermarket tow hitch install and while the tow bar itself is a good unit, the tow module to control the lights is not nearly as good as the factory unit. besides hacking into the wiring system, the aftermarket tow module does not switch the transmission programming to assist with the extra loads which might cause problems when towing a bigger trailer.