If you do paint it make sure whoever does it uses a primer wth a slow catalizer like PPG DP-90 with PPG_401 after sanding. Normal fast catalizing primers are for steel slow are for aluminum. Thats why people have issues sometimes with painted aluminum. Just a thought.
Truck looks good man. Polishing aluminum what a mess. Done alot if trim in the past for restorations. Black everywhere.
Have had good success on sealing aluminum with Zoop Seal you can get it through Eastwood or Zoopseal.com let them know the size of your project. Works great on non clear rims as well. They "claim" two years protection but we've always done it yearly. If this was mentioned in the link, sorry I couln't open it for some reason.