GRS444, it's probably already as accurate as it needs to be for what you have in mind. That match barrel should do sub moa easily. Adding a float tube could help a smidge, but I'd just drop an RRA trigger in it, and figure out what float setup you need. The FIRSH is probably perfect, but you'll have to get the brake off to install it...if you can do that yourself, then the FIRSH itself is only $125 or so. If you don't want to mess with removing the brake, then try the SIR...it's a lot more expensive, but at least you don't have to take the brake off or pay a smith to do it.
Unless you don't like the profile, I'd just leave the front sight on...you're not gonna see it through a scope, so why bother changing it out? If you do change it, a removable block is around $35 or so, depending on which one you get...but once again, the brake will have to come off to install it.
Just get yourself a SIR, mount the stuff you already have to it,then work up some good hand loads. The best way not to make your AR look like Huggy Bear's Eldorado is just not to put the stuff on there!