This will be the best option.. Identical speakers for bed channels. I have 5 x LCR 60 SL for bed channels..
Don't think you would be able to locate LCR 60 SL.. Few months back, i tried and couldn't do it.. Please check again with dealers, online.. Incase, you locate, you would be lucky. to have identical speakers for L-C-R.
You can look for alternate options like BS from Taga Platinum range (v2) for fronts to timbre match with center.
Audiomaxx website --->chat with them, i checked for prices 2 weeks back and they confirmed audiomax can arrange LCR 60 SL, You should be able to negotiate for better prices, They quoted me around 19500/Per speaker, But if you are getting 4 X LCR 60 SL they you can get around for 17000/Per speaker.