I went to my local Honda dealer, and asked the parts department about the difference in caliper pistons between the left and right front calipers. Their computer showed two different sets of seals and pistons, so I ordered the seals for the left caliper that I needed, and then I bought two new pistons for the right front caliper, and two new pistons for the left front caliper.
On reassembling the calipers, I did have a little trouble getting the new pistons into the caliper. I thought this was good, since it probably means that it created a good seal. I just used the brake fluid to lubricate the caliper pistons when inserting the pistons into the caliper. That may be why it was difficult to get back in.
I did notice that my brake like was very slowly leaking from the banjo bolt on the front left caliper. I put it back on properly (with one washer above, and one washer below the brake line) and tightened the banjo bolt very tight. The leak from the banjo bolt is very, very slow. If I leave my bike sitting overnight, there is only one drop of brake fluid on the floor the next day.
Also, my front brake handle is a little spongy and soft, which most likely means that I have air in there somewhere. I did what I read on another forum, which was to compress the brake handle overnight, and then bleed again in the morning. I was surprised at how much air came out the next morning! I did this with both the front handle, and the pedal brake.
I'm not too worried about the sponginess, as this is exactly how the brake felt when I bought the bike about two months ago. Plus, it makes stopping a little smoother, but I can still stop on a dime if I pull it hard enough. But, when I get some more time, and maybe an extra hand, I'll try to get more air out of it.
When bleeding the pedal brake, I only had to bleed the right front brake. It didn't seem like I had to bleed the rear brake (even though on my 1983, the front and rear brakes are linked). However, my brake pedal was sticking, and not returning to the resting position. So again, I read another forum on here where someone said to use WD-40 and work the pedal back and forth to get the gunk out. I removed the pin from the rear brake and the little spring for the brake light to allow more leverage when working the pedal up and down. It only took about 5 minutes of spraying WD-40 and working the pedal up and down for it to free up. Now it works as good as new!
As OnaWingandaPrayer stated "Your left front caliper will use the same kit as the rear of your bike . ITs the right front that has the smaller pistons." I looked at my rear caliper pistons and they look like they could be the same size as the front left calipers, but I didn't take my rear caliper off, so I don't know for certain, but it would be a pretty good bet that they are the same size. I wouldn't have even thought to think of this, so thank you OnaWingandaPrayer!
As for the speedometer cable replacement, the one I ordered from Saber Cycle fit like a glove. The speedo cable fit really good, and I haven't had any problems with it (I've been using it for a week now). I bought some white lithium grease that came in a spray can to lubricate the speedo cable.
Now, my tachometer cable is whining, and I can't figure out how to get it off from the engine to lubricate it, but I'll post this problem on another forum, so if you have a solution for this, or want to follow that forum, just do a search for it (1983 GL1100 tachometer cable).
Thank you everyone for helping me through this process. If anyone is going to be performing this work and needs some help, feel free to ask!