Bog death grip would be good for that situation. Heavy as sin but perfect if you aren’t carrying it far, they are super solid. I think the newer ones have the ability to convert to optics mounting plates.
You say a shooting shed but are you going to be shooting your rifle from the tripod? Are you going to be hiking distance with the tripod or will it always stay in the shooting shed? These questions will help with deciding on a tripod.
As far as heads go, If you are only going to be glassing with no shooting I prefer a pan head. If you plan to shoot from it I prefer a ball head. I prefer ARCA over the other mounting solutions.
If you don't have to carry it far the imported tripods like Feisol, Leofoto, etc do work well and are good tripods for the $$. They just don't have the weight to strength ratio like the stuff from RRS. If you want lightweight for packing RRS is the ticket.
Regardless of whether you go import or not, an RRS ball head is absolutely worth the money over the imports. The imports are trash in comparison. They are so smooth and don't freeze up in low temps. I would get a lever release version and then arca plates for your spotter and LRF so you can easily change between them if desired. Also an arca plate for your rifle because shooting off of a tripod is money.
Not sure if you’re going to be shooting off it or not - but I really like my Innorel RT90C tripod. It’s fairly heavy, but a fraction of the price of an RRS tripod…and still very sturdy. I did put an RRS Anvil ball head on it tho, and I feel that really makes the combo nice. The RRS ball head is spendy but it’s a cut above for sure. I use it with an S&S ARCA mini rail.
I just got the Revic Tripod and ball head setup this year, and have been pretty happy with it. About half the cost of the RRS stuff and seems to do everything I need really well. Had been using a smaller Silk model and like the new one better. Shot my Wyoming Elk from it this past October using a Spartan Arca adaptor.
If you get a chance to go and handle a few tripods, camera shop, hunting store, etc…. I would suggest that you look at trigger style heads as well. For only glassing ball heads are likely not the best or easiest, Fluid pan heads are really nice but not as quick to center view, the trigger heads are really quick to center on your view and solid. Since you are not planning to pack this in weight is not such a concern, so that would allow you to find a cheaper tripod.
Do you already have your SS or RFB’s, and your bino attachment? Those things could affect which option works best for you.