I learned to process film with plastic reels and tanks and it worked just fine. Later on, when I worked in the darkroom at work they used stainless reels. Once I used stainless, I liked it and converted my own film processing to stainless.
Film loaded faster for me in 35mm and 120 using stainless reels and cleanup seemed better.

I would recommend Hewes reels. They work the best for me and are highly regarded. Found some here:

http://www.freestylephoto.biz/140120...-Reel-120-size

and

http://www.freestylephoto.biz/140135...teel-Reel-35mm