Converting an RC kit or plans to CL can be done. I have lost count on how many RC ARF's, kits or plans I have converted and flown as a CL model. I tend to move the CG forward from where the RC plans show.
Outerzone is a great place to find plans, you will be surprised on what you will find. Download the plans and then take the file on a thumbdrive to Fedex Kinkos to get a print made of the PDF file.
Install a line guide so that you get at least three degrees of line rake and the wings are level in flight. The bellcrank location is not critical because there is a straight line between the handle, line guide and CG of the model. Move the CG aft and keep the line guide in the same location and your line rake is decreased.
if the line guide is too low or high it will affect how level wings are during flight. My pratical limit on the weight of the model is 15 lbs, but CL scale allows up to 20 lbs. The heavy models pull more than the average ringmaster but that is why you install an adjustable line guide to control how much line tension you have. You want enough to keep it out there, but not too much that you are being dragged out of the circle.
in the video below I show how to hang the model to check line rake, you can also use the same process when looking at the front of the model to see if the wings will be level or not.
Fred