The "A" Light Sporter and the AB Light Standard Sporter is also rare.
They did make the 223 as a "B" Standard Rifle for a bunch of years. It is now discontinued but I think all the "B"s are 1:12 twist.
They also made the "V", the early ones up till 133-xxxxxx have 1:12 twist rates. The newer ones are 1:9 to stabilize the 69 grain .224 bullet. It doesn't stabilize/shoot the more common 40-50s and 55s. Both the "V"s have 24" barrels. I sort of like the "B" a bit better than the "V". A "B" with a 26 barrel and the .224 hole down the middle weighs right at what the heavier profile but shorter "V" weighs. I've always opted for the "B" for the extra 2" of barrel.
The longer barreled 223s do come up and cost less, compared to the 223 in the "A" and "AB" rifles. That said the "V" and "B" are starting to sneak up in price now that both are discontinued.
I'd think you biggest choice is do you want to shoot 40 -55s or 69s??? That will determine which 223 #1 you really want .
Remember a 26" barreled #1 is the same length as MOST bolt guns with 22" barrels. A 26 is actually handy but the 22" light barreled ones are QUICK. I have 2x7-28 Compacts on my light ones and that makes a very small and handy package, BUT unless you get lucky you'll pay a premium for either the 223 "A" with sights or the "AB" no sights but the semi beavertail for rare and usually they demand a premium. Especially as the rarity is recognized. I paid $550 for a 223 "AB" about 8 years ago. The last one I bought was right at $1500!!
As gwehr mentioned the "AH" light sporter but no sights, is a really handy walk around varmint rifle. ;-) Just have to find an "A" or and "AB" to start with.
Good luck
Ross