What catburetor should i use on a 125cc Lifan 4 stroke

Hi
I have a little problem by choosing what carburetor should I put on my Lifan 125cc 4stroke engine. I don't have enough space due to height restriction . I have search the internet to see what size carb they use and the majority tell 24mm . I can only use from 19mm to 22mm . Can anybody tell me what's the best and what is the effect of each one? I don't care about top end speed , I only like torque . Am thinking of this
http://www.ebay.com/itm/22mm-Cable-Chok ... lw&vxp=mtr

Talk to Adrian at www.00Racing.com.He's in the UK in Kent.
He supplied me with a Molkte carb.and matching airfilter for my Lifan 125 in my ST70 frame.Brilliant piece of kit.Not a lot of room to accomodate the pipework but works a treat.
Send me your email address and I'll send some pics of my bike.
Brian

Thank for the tip.
My bike is Honda chaly cf50 . I have attached some pictures for reference. At the moment I have 26mm but the problem is that the top of the carburetor is sticking out from the chassis causing me problems with the police . I have the plastic carburetor cover (see picture ) but not installed at the moment . If I change my carburetor from 26mm to one of 19mm or 22mm there is no problem, I can place the cover and hide the carburetor . The only thins is I that which is the best of my engine and what is the effect of each one?