Making cosmetic changes brings with it many opinions. For me, if it doesn't make the rifle shoot better or feel better, I wouldn't bother. Fluting a bolt always seemed silly to me but if its something that intrigues you and you have the cash, go for it. Some do it just to lighten the overall weight 1/8 lb
H-S Precision is responsible for making the stocks you get with varmint models from remington, that would be the VS, all older Senderos, VSF, VS SF, VS SF II, Sendero SF II, and the Police/PSS. If I left any out, someone will correct me. Just make sure that when you get a barrel, check to see if it's a varmint contour or a thicker bull barrel. The stocks only accept certain ones so it's important in the long run.
I've never bought a rifle and tinkered with it but I am doing so next week. I'm getting the very affordable SPS Varmint. The only weak link(if you want to call it that) is the plastic stock, so I'm throwing a H-S PST12 Police stock on it. The SPS-V comes with the new trigger and the matte finish is the same as the Police models. Even with that cheapo stock, it's getting .700 groupings, and they shrink to .3 and .4 in reviews when they simply slapped a H-S tactical or varmint stock on it.
It's not custom but for me it'll be a different experience. Heck, if I get it home and it shoots .5, I'm may not change a thing
Oops, this was about your custom build, sorry I got carried away!
**I have never looked at barrels that were seperate. Google is your friend.