Way too small - just one BGK - temporarily while you get a bigger tank.
I plan to try to keep a few smaller BGK in a 200+ - LOTS of caves and fairly well planted - driftwood - rocks... etc. so that the will each have enough territory.
I want to get about 4 small (3 inch) BGKs and grow then out together. I will however ensure that I have extra tanks available if any sort of problem breaks out - hopefully I will see problems developing but I also understand that I may wake up some morning to a Single BGK.
I have had my 'Shadow' for almost two years now and I love him to bits. I am willing to take some calculated risks in hopes of being able to get a breeding pair, but I am not willing to risk my big boy. I have also read that once they start to get some size they don't like to be moved from tank to tank - they don't always acclaimate well - so I suggest that you put yours into the tank that will be their home for life.. that is how it worked out for me.
I also work from home and spend most of my free time around my tanks or on this forum

I have done a lot of research and planning - and will be spending a lot of $$$ on a large tank when the right one comes along.
BGK are IMO the most beautiful and graceful fish I have ever seen. My BGK now owns the 72 bowfront - with a few corys and larger tetras. He has ruled that tank since the day I got him... not by force - it simply became 'his tank'.