plasti dipping

Having them dipped, more then likely won't last and in the end, probably not that much cheaper.

As far as the spray bed liner, that's a new one or me. For starters I think I would add unnecessary weight, may look like jenky and who knows how long it will last???

Honestly, to do it right.........just have them powercoated. Time really isn't a factor with it being summer and as far as cost, just do a part or two as you go and stretch the cost out. In the long run, I think you would be happier and some day when you go to sell the sled......it would probably easier to sell too.

Just food for thought, I know tons of people haven't had issues, but I had my rails powder coated, along with my torque arms. And A-Arms. Rails folded up as I left the parking lot on the first ride. Wasn't much longer that the A-Arms followed suit and the torque arms I noticed last ride that the rear one is bent. Just seems like too odd of a coincidence to not be tied to the powder coating.
For bumpers that may not be an issue. BMFAB makes some amazing stuff and can powder coat for you. Zollinger Racing Products will anodize to some pretty slick colors.
Everything that folded up on me was a Polaris OEM part.

I had the top of the tunnel and my side panels dipped years ago. Looked good when new of course, but wear shows now. Some talked about several layers of clearcoat to make it stronger and slicker, but I never did.

All I can say is there are many scratches on top of the dipp that would otherwise have been on my paint..

Top of tunnel, not so great. Any fuel spill will dissolve it and you smear your bibs and boots.

As mentioned here, powdercoating Alu has to be done RIGHT, meaning a low temp version. Ask people in the know, as I am not. I just read about others trying here on the forum.

Other paints can yield good results with good prep (always etch-prime alu!). Personally I used some kind of wheel paint ages ago with good results.

Luck.