JRSR126,
First thing you want to do is make sure your Sidekick is rated for a 495gr conical. My Huntsman has a maximum recommended weight of 470gr conical and 80gr powder charge. I remember somebody saying the Sidekick max is a little higher, 490gr maybe?
With a 1-28 twist, I am not sure you will get a very long conical to stabilize. Most of the 495's and up shoot better in 1-24 twist barrels like my White. That said, the 460's shoot good out of my Huntsman. I have never shot anything heavier out of it. My 1-24" White will shoot up to a 600gr conical.
Just remember when shooting all lead conicals, you don't NEED a lot of powder 60 to 80 grains is plenty. The felt wads will definitely improve groups in some rifles, you will have to find that out for yourself. The wads do cut down on leading and will let you push the bullets a little faster usually. Either of the bullets should work well enough at ranges <100 yds, and is plenty medicine for anything in North America.
If you get the No Excuses, get the .503's that are standard. These fit well in the Huntsman, slip-fit with light engraving on the way down. These will obturate into the rifling at ignition of the powder charge. These are some of the best conicals out there, and I have shot plenty. If you order 2 boxes of conicals at NE, you will save a little on shipping. Do you have a link to No Excuses site?
Let me know what your max loads are for the Sidekick, please?