Wow, now I see what you are talking about. I checked the websites for LG and Samsung BD Players, looking for specs and I was shocked at how little information they give. I clicked on two different models at each site and none of them indicated what WiFi standard was being used. I checked the product specs and I even downloaded the User Manuals and none of them mentioned G, N or anything that would indicate. Some of the more expensive Samsungs claimed Dual-Band so they are undoubtedly N since that's what you would use on the 5GHz band.
Anyway, I think it would be safe to assume that any current model year BD Player with streaming capability will be wireless N. They have to have a strong enough connection to support HD content from Amazon, NetFlix, etc. and I don't think the manufacturers would risk the technical support nightmare that you'd get from trying to cheap out and put wireless G adapters in them.
That being said, there is a huge difference between an Amazon/NetFlix/Vudu/Hulu HD stream and a BD rip. The services will max out at about 8Mbps but a BD rip can easily peak at just under 50Mbps, most will have an average of 25-30Mbps with higher peaks during high action. Any GOOD wireless N connection should be able to handle it, but that would require same or next room location between the router and the BD Player as additional physical barriers will cause significant decrease in available bandwidth. I would bet that most of your BD Players have n150 connections that have a real life max around 60Mbps under ideal situations. If somehow, some way you can verify n300 and your router supports it as well then you should be OK.
In general, though, BD players are a poor choice for streaming local content. Dedicated devices are much better for this. Even a RaspPi2 with a proper n300 wireless adapter and taped to the back of the TV will work better. That's what I use in my master bedroom and it is very, very good. If you are going to insist on a BD player and just can't get the wireless working reliably you may need to consider something like Powerline or MoCa adapters to create a wired network.
One other option, if you are running the rips from a centralized server, you may want to consider a DLNA server that can transcode on the fly like Mezzmo, Serviio or Universal Media Server. They can be set to reduce the bitrate for your BD rips and make it easier to avoid network congestion. You'd need a pretty powerful CPU in the PC that is acting as the server.