RCBS and Dillon are probably the best (Dillon probably #1).
I'd stay away from any Lee presses. They work, but they aren't built to last.
You need to figure out what you are going to be shooting and work from there.
Are you going to be hunting, plinking, or target style shooting. You'd have to research the most accurate projectile for your style of shooting and then use the load tables to find something that fits your needs. Or, register at AR15.com and browse there.
I'll debate the Lee Press Statements. I know a LOT of people that have been using the Lee Single Stage Press for over 10+ Years.
My suggestion is that you go out and buy a Hornady Reloading Manual. They are about 30 bucks and will give you a lot of information that you will need to reload.
MOST people use Hornady Bullets anyway, so having their reload manual isn't a bad thing.
(I Know that you have a hornady book now, but is it the most current one?)
Reloading for the .223 will cost you some money. Basically for the cost of the bullets, powder, the primers, the equipment, you'll never really get your money out of it.
Example, assuming that you have your equipment already:
100 Hornady Bullets (.224 V-Max 55 Grain) (At Bass Pro for example) Is $25 bucks.
1 pound of Hodgdons BL-C(2) Powder (Known as Ball-C which works well with .223) is Roughly $25.00
100 Small Rifle Primers 7-1/2 Remingtons $3.00
ASSUMING YOU have 100 Empty cases (Free)
$53.00 + tax .. Lets keep it simple and say $60.00
You can go out and buy 2 boxes of 50 count Hornady 55 Grain Softpoints or FMJ's for $25-27 dollars each. (Brass cases, not the wolf stuff).
For 2 boxes of factory ammo, you have the same cost as if you reloaded. Thats tough to beat.
NOTE: I still reload .223 because I like reloading, however, if you step up to other calibers, such as .308 as a example, you'll be able to make rounds cheaper than you can buy factory loads for. (Now if you compare Russian ammo in the cost per round, you'll might as well buy russian ammo, because you can't reload it cheaper than you can buy that steel case stuff.)
IN MY OPINION : If you are just going to reload .223, you might as well buy the factory hornady 50 count boxes. If you want to reload for a new hobby, then go for it. If you have multiple calibers, go for it.