l guess I didn't really answer your question about POLISHING the intake... I love the look but man it takes SO many hours to polish aluminum that I typically avoid it since I'm not really into building showcars
You definitely want to use power tools for most of the work, various different size sanding drum wheels, cone wheels, multi-tool to get into crevices, start with 80 grit on a power tool and work up to 600, then you sand by hand with a piece of sandpaper, for a mirror finish you need to work to about 2000-2500 grit. Expect to spend 8-12 hours of ACTUAL WORK TIME doing this.
The worst part of polishing aluminum is once you start you are COMMITTED to finish the project or it will look like *** if you settle for anything less than a mirror finish... set up a little water drip (or spray with those little garden mist sprayers is even better) for the hand sanding, you'll get more life out of the sandpaper because it won't clog up with aluminum dust.
WEAR A MASK or set up a fan outside to blow dust away from you, fine metallic powder is terrible for the lungs.
I'm committed to never polish another engine component for as long as I live, after you've done a couple you will feel the same, if I do ever decide to polish again I will either pay someone else to do it or invest in a vapor blasting cabinet. Not a huge fan of glass blasting because of how it embeds so much crap in the surface as well as the amount of material it removes but it's great for extremely corroded parts that have a lot of rough work needed. Vapor blasting leaves the best finish imo.