Brining is a good idea. You can smoke/roast it but I wouldn't suggest low/slow.
Cook as you might a conventional loin with a fatcap, i.e., score the fatcap first, salt and pepper all over, then apply your rub of choice (I like herbes de Provence with boar, or a thyme/garlic/onion-based rub. You can sear the loin first in oil then apply the rub, rub and then sear, or skip searing and roast directly. I'd suggest a roasting temp of ~325 at the grate and cooking to an internal of 144-146.
Frankly, I'd skip the bacon. It will not help to retain moisture if placed inside and, cooked to a lower internal as best befits loins, won't cook very well either. Bacon on the outside can reduce evaporative pressure on the roast but I'm not a fan of this: the rendering fat bastes the outside of the roast only, doesn't add much in the way of flavor and, as it covers the meat, blocks any flavorful baste you might wish to use. It also covers any applied rub.
I'd consider a water-based baste rather than an oil-based one. An oil-based baste will speed cooking. Though cooking at a moderate temp is quicker than cooking at a low temp there's a limit to how fast one should cook a loin. That said, some fat here is helpful. Consider 4 parts liquid to 1 part fat. One that should work well with an herb-based rub:
Render the fat from 2 slices of bacon by cooking it over low heat. Pour off almost all the fat into a small measuring cup, leaving just a touch in the pan. Return the pan to the heat, increase it to medium, and saute 1 T of minced shallot just till soft. Add a pinch of thyme, a small bay leaf and, if you have them, 2 lightly crushed juniper berries. Add a 1/2 c of dry cheap white wine and bring it to a simmer. Reduce the wine by half then extract and discard the bay leaf and the juniper berries. Pour the contents on the pot into a blender and add 1 T Dijon mustard. Blend briefly to combine.
Add enough oil to the reserved bacon fat to total 1/4 c.
Add 3/4 c cranberry juice to the shallot-Dijon mix in the blender and turn the blender on. Add the oil in a slow steady stream and blend just till emulsified.
If using a kettle or WSM: Lift the lid straight up with one hand just high enough to access the roast. Baste quickly with the other hand then immediately return the lid.
Hope this helps. Good luck.
