first things first. get the pedals and stuff around them all completed and then worry about the inner fenders. just keep in mind the general shape of the inner fenders when mounting etc.
after that, when ready for fenders, grab some stiff cardboard, like a fridge box or whatever, and see if you can shape it around the components you have in place. the nice thing about that is the cardboard isn't stretchable, like sheet metal isn't, so if you can make it from cardboard then you can make it from sheet metal. when done, if unsure, get a fridge or freezer door and see if you can fashion something from that. if it works, you may even stay with the "model" or take that to a sheet metal place and have them run a few edges through the break for nice clean bends.
something to think about when doing this is the extreme movement of the suspension. it will be harder to do with the springs in place but you should consider how much the suspension travels upwards. leave some extra room to compensate for that. roll the edge on the opening in the inner fender with a hammer and dolly. then, because the opening will be bigger than you probably would like to see under the hood, you could hang some reinforced rubber around the opening with some plastic autobody push pins so the rubber will cover the suspension parts and keep the splashes out of the engine compartment, but will also move out of the way when the control arms move over bumps etc.roll the inner fenders edges into the engine compartment side if you want the rubber on the wheel side of the panel and vice versa. that would keep it clean and look like it was made like that.
here are a few pics of what my inner fenders look like on the 57. it's a frame swap so many differences for sure, besides the year, but you can see that even though I used stock inner fenders the job could also have been done with some flat sheet metal. the opening for the suspension is large but will be rubbered up on the wheel side of the hole. I used a hammer and dolly around the hole after scribing a line at 1/4" in from the edge. if you have access to a bead roller the indentations for strength would be easy to roll in where you want them or simply tack on some 3/8" 16ga angle strips onto the wheel side of the sheet to add strength.
you may wanna look at the gmc envoy or chevy trailblazer pedal assy. it bolts through the firewall into the brake booster and has the brake pedal and also a flange for the drive by wire accell pedal mount. that could be modified to accept a different accel pedal I am sure, if that is what you are running. it is supported at the dash end as well and could be easily modified for your purpose I think. below is a link to a set for sale on ebay that has pics.
https://www.ebay.com/itm/Chevy-Trail...-/252915236680