going to put put in deticated ac,are there any differances in breakers that are available you guys have found,already heard tremendous differance in outlets,need to go to next level with i need 20 0r is 15 amp just fine,thanks.
Go with 20 amp, because you just never know when upgrade will hit..
Get 20amp. They're not that much more. Other than that I'm not sure the break matters. I don't think I've read anything about any boutique breakers on these forums. I have read about boutique (read: cryo) in-wall wiring though.

Also get some Walker SST or the newer Extreme SST. Have your electrican paint the SST on all of the bare metal contacts. Just tell him it's "electrican's paste" albeit much higher quality.
I went with 20 amp breakers that fit my panel. That is your limitation you usally can't mix and match breakers with a panel. While you are at it ask for 10 gauge wire not the usual 12 gauge used for 20 amp circuits. That will certainly make a difference. Also have the ground run back to the panel you can do that by using non metallic boxes. That is very helpful if you are running more than one circuit/plug which is suggested. I ran three wish I had did four: 1 for the amp, 1 for the digital, 1 for analog. Hope this helps.