Hi Jesse;
The best thing I had the riggers put in my suit was a vent in the back of the jacket. had a rectangular hole cut below the shoulder blades and then strong no seeum netting sewn in, had the same done to the top of the boonie hat...much cooler now. also had webbing sewn around waist in jacket to attach holster and other light items inside the jacket with TA50 clips. For an item used less than 10% of the time, still need to be a comfy home when it is used.
One thing I did do different is I used the 6 color desert BDUs as a base all pockets removed from jacket(they'd be under the skid plate anyway)with two relocated to the upper arms above elbow and forearm pads, trousers all pockets useable with padding and leg skids sewn to allow their use. The idea of the 6 color desert is like an animals belly, light in color to help lighten the shadow under you. Plus most of the stuff you'll be stalking in is more tans and browns than green. The addition of thumb loops, stirrups, and loops at the bottom of the jacket(run 550 cord through them front and rear for a ruck strap to keep jacket down like strap on Brit smock)this keeps the whole thing down when in reverse gear, and completes the base suit.
While on the subject of the Brit Smock

The british Sniper Smock is a great item, has padded forearms/elbows, upper arm sling clips(both arms), padded shoulders, para crotch strap, bottom pockets located at the sides(so not under you), knitted cuffs(keeps creepy thingies out), and has ghillie loops already on it.The snaps for pockets and such are built like tanks, and has a heavy zip front closure with snap wind flap. Have used one for quite awhile and have to say you'll use it more than any ghillie suit. I team mine up with a boonie ghillied up, and you travel light and when you want to blend in with the rest of a patrol ya just remove the burlap and, viola! Ya look normal! Well some of us will look normal:eyeroll: It's a great piece of gear and much more useful than the ghillie.
A ghillie is a must have item for a sniper, but it's also the least used item. Taking from the British a set of BDUs with several well placed nylon flat sewn loops in the right locations will serve you more and better...and with a lot less gear to carry

Beats the heck outta the cutting slits in your BDUs to loop your camo...hate a "Get the heck outta Dodge" with my shorts blowing in the wind

To copy the sling clips, the new quick cuff sling's cuff can be sewn to the upper arm with a couple loops of thread to keep it from moving(get a brown one not the shoot me black). Plus this also looks "normal" to your counterpart in the bush, just another GI. May not be as "glamorous" as a Berenger suit but does the job.
Just a couple of ideas, hope they give you some food for thought.
Take care...Jim