I was also looking for a 125 g tank way back when until Four-by-Ken suggested that I go bigger, the 125 is on the smaller end of that footprint (72" long) so why limit yourself. After mulling it over I agreed and went up to a 180. Basically the same foot print (72" x 24"x 24"). Thanks Blair - My bad ! dooo
IMO - look for an entire setup being sold on CL. There are always people getting out of the hobby who will sell everything.
FWIW - I got a 180, wood stand, FX5 filter, glass tops, 2 heaters, 2 - lights, all his decor, 10 larger African cichlids and ALL the supplies for $500 total...You just have to be patient and find the right deal. BTW - the tank was up and running with fish in it when I went to look at it.
Good Luck !