Setting up a bichir tank

[Ryodraco]

Hi all, I joined today because I wanted some advice on tank set up and this is the most active fishkeeping forum I've found. You see I have fallen in love with bichirs lately and want to set up a tank just/mainly for them. Thing is I've never owned a tank larger than a 50 gallon before so setting up a big tank is a new thing to me. The expense especially is a bit of a problem.

But anyway there is a deal at a local fish store for a Aqueon (I think that's the company, also All Glass is on the label) 125 gallon (72 inches long, 18 wide, 23 high) tank with stand, glass top and lights for only five hundred dollars.

Question is would this be big enough for what I want to put in it and if not then how big of a tank would be needed? I'd rather avoid having to buy a larger tank later on as the fish grow. I am avoiding most of the larger species of bichir in my considerations.

This is the set up I am considering:

Senegal bichir x1 (grows to about a foot long)
Palmas bichir x1 (grows to about a foot long)
Delhezi bichir x1 (grows to about 14 inches at most)
Ornate bichir x1 (grows to a max of 2 feet or so)
Reedfish (AKA ropefish) x3 (thin fish that rarely grow more than 20 inches in aquriums)
Magnum Canister Filter x2 (each rated for a 100 gallon tank)

If this is too much for the tank I described then what of the above could be kept in it? Could a 210 gallon tank (72 inches long, 24 wide, 29 high) be big enough?

I've been getting mixed information searching on the internet. I've seen it said that even an ornate bichir can be kept in a 75 gallon tank so a 125 gallon one seems like it should be enough for one and some tankmates.

Thanks in advance.