The Lemo, IIRC are supposed to quite good connectors. But in order to be compatible with existing equipment, you need to stay with one or the other, unless you want to change all your plugs/jacks. Given the choice, I would go with RCAs, unless it is digital, in which case I would do BNC. As for good value in RCA connectors, you didn't indicate whether you needed plugs or jacks. For plugs, the Neutrik ProFi are a good plug and a good value. For chassis mounted jacks, I've used Cardas, Dayton (partsexpress), etc. The Vampire solid copper jacks are supposed to be good, but at $20 each, I haven't used them.