disk swap on '74 or keep drums?

I'm relatively new to working on cars. I have a '74 Swinger with 4-wheel drums. I don't plan any high-performance driving, but I want a reliable and reasonably safe daily driver. As far as I know the drums and even the shoes are original (80K miles on the car) but I have recently replaced the 3 rubber hoses and the master cylinder. The car has always been garaged and is virtually rust-free with undercoating. Right now the car stops just fine, but there is a rubbing sound on each wheel revolution when driving (I think the noise comes from a rear wheel--it goes away when pedal or parking brake is applied). Based on my research I think I have 3 likely options.

1. Keep drum/drum and replace components (drums, shoes, wheel cylinders). Easiest and cheapest option, but doesn't give me disk performance.

2. Swap to '73+ disk brakes on the front. This isn't too complicated, but the problem is you get the 4.5" bolt pattern on the front. I'd need new front wheels and if I want the rear wheels to match I'd have to replace the rear end with the 8 1/4 rear that was on the '73+ disk brake cars. This seems really expensive.

3. Swap to Kelsey-Hayes disk brakes on the front. This keeps the 4" bolt pattern, so I can keep the same wheels and rear end. However, I'd have to swap out my '73+ upper control arm for the smaller '67-72 UCA (or is it '65-72?). This seems like a good choice depending on the cost. I just paid to have the upper ball joints replaced, so I wouldn't be too thrilled to have to swap them out.

4. Get an after-market disk swap kit with 4" bolt pattern. This is probably the easiest but not necessarily the cheapest or best option.

What do you all think? The existing drum brakes already provide enough stopping force to lock up the wheels if I really stomp on the pedal (I tried dry pavement at 30mph), so do I really need more stopping force?

Are the '73+ drum/drum systems adequate for modern driving if you don't plan to race? I get that the older systems are not so great, but are the later A-bodies OK with drum/drum?