in too deep: trying to go BBP on a 68 barracuda and its going.. poorly.

Hi! First off, im new at all this. I wanted a muscle car project, and always loved barracudas. So.. i recently bought a 68 barracuda with a 318/auto thats been sitting for a while. The brakes are a mess, the tires are garbage, and its a 5x4 bolt pattern. I want to drive this thing in highway traffic, i want decent braking performance, and i want wheel and tire selection. I figured i might as well go to 5.4x5 as it shouldn't be too difficult, right?? The initial plan was buying a disc brake setup for the front, and leaving the drums in back. Sounded fairly doable. I bought the hells gate hotrods jig to drill the rears to fit 5x4.5, and also bought 5x4.5 wheels all round. Also a 5x4.5 front disc setup. So, i have all this crap in my garage now, and finally have a chance to start drilling. Anyway, today i discovered that the rear hubs have these big holes in them right where one of the bolts would be going. I also managed to break the pilot hole drill bit in the jig cause it caught the edge of the hole on the hub it was going into. So now what? Looks like i cant drill these after all, and will need new axles i guess?
BUT im not sure what i need for that to happen or what axles to get.
I have an 8 3/4 rear end, 714 carrier, which i believe means i have a 10 spline? which means i cant use the dr diff axles? also im not sure if this is the original rear end, from what i understand it might be. might.
moser sells a set i saw from elsewhere on here, will these work? A30-CST-A45 - A-Body, 8 3/4" Rear Axle Shafts, Stock A-Body Drum Brake (Redrilled) -- 30 (Pair) - Moser Engineering if so thatd be great, im hoping to re-use the rear drums. tryin to keep that budget down..

also i dont want spacers. rears are 15x8 with 245 tires, not sure it would fit on there with spacers.

So, anyone have an idea what i should do here? id prefer to keep it cheap as possible, i still have more crap i need to buy. i haven't even been able to drive it yet! it runs, so im hoping its fine. it wont be, but i can hope :)

attached are a few pictures, cause pictures are fun! it looks nice but its hiding all the rust :D
last pic is where i broke the drill bit on the hub trying to make new holes..

It would have been a lot easier and cheaper to keep the small bolt pattern axles and brakes. If you have an 8 3/4 rear they are good for 400,000 miles with only lube changes. You can get premium brake shoes from Firm Feel and have good braking and change nothing, assuming you have 10 in drum brakes all around. I have been through this too many times back and forth with my own cars. The 66 and 68 Barracudas have 5 on 4.00 bolt circle 8 3/4 rears, Kelsey Hayes front disc brakes, and 15" wheels. My brothers 67 Barracuda has the 5 x 4.50 bolt circle and there is a lot of time and money to get it right. Maybe get good tires and custom wheels with the money you save...