Glad we could be of help to you.
In my opinion, you don't need one of those "outside the gun" loading presses, at least not right now.
They are nice to have if you own a Paterson, a 1848 Colt Baby Dragoon or one of the other Colts that doesn't have its own loading lever but if your gun has a loading lever you can use it to load the individual cylinders and then remove the loaded BUT UNCAPPED cylinders from the frame.
As for buying three extra cylinders, that is an individual choice. Personally, I wouldn't spend the money because I can't think of a time that I would be firing 15 shots in a row. (I always load only 5 shots per cylinder).
When you say you are going to use patches I assume you mean you are going to use them as filler between the powder and the ball?
That's OK but figuring out just how much patching material into the chamber under the ball isn't easy. I have no idea about the size or number of patches you would need per chamber and of course, this will change if you change the basic powder load.
EDIT:
The measuring methods consist of just getting a adjustable black powder measure.
These usually have a sliding rod that can be raised or lowered to change the amount of powder that's measured. Once changed, the sliding rod is locked in place with a little thumb screw.
The size of the powder charge is marked on the sliding rod with little numbers.
The small pistol size that measures between 0 and 50 grains of powder will be the best size for your gun.
Another option is to buy one of the metal powder flasks that are sold by Dixie and some other suppliers.
These come in actual recreations of the original flasks with embossed designs on them.
The spout is removable by unscrewing it and additional spouts in different lengths to "throw" larger or smaller amounts of powder are cheap and available.
One of my favorite brass flasks isn't really traditional. It consists of a round brass tube with a removable cap on the bottom and a thumb operated gate on the top. As I mentioned, different size measures just screw onto the top.
When I'm shooting my revolvers or my rifles at the range, I use this flask to measure all of my powder, changing the measuring tube to match the gun I'm shooting.
To measure with these flasks you put your finger over the end of the measuring tube, then use your thumb to push the little gate lever to the side, turn the flask upside down and give it a few shakes.
Keeping your finger on the end of the measuring tube you then release the little gate with your thumb and turn the measure right side up.
Walla! You've got a measured amount of powder ready to dump.
Here is where there will be some controversy, but if I'm loading a revolver that has not been shot for 1 or 2 minutes I will pour the powder directly into the chamber.
If I'm loading my rifle I pour the powder into a secondary powder measure and then pour from that secondary measure into my barrel.
The way I figure it, a revolver that has not been fired for a minute or more has very little chance of a glowing ember down in the chambers. Plus it is easy to see all the way to the bottom of each chamber to look for anything that is still smoking.
A rifle on the other hand is hard to see clear to the bottom of the barrel and if there is a chance of a glowing ember down in there I sure don't want to have a fully loaded powder flask right where the newly dumped powder charge might be firing. That's why I always use a secondary measure to transfer the powder from the flask to the barrel.
