I have had my two gourami's in my 55 gallon tank for quite a while. One is male, one is female, and the male is always chasing her around, but he never does anything nasty to her or anything, he just likes to chase her like a jerk. One of them will have a new home soon since the stress has mounted to an unsafe point on my girl.
I got them both at the same time, different tanks(one is the normal blue variety, the other is gold), they were both about three inches then. In the last five months or so they've both grown more than an inch, the male has grown nearly two inches being about five inches now. I think they're done, not sure though, they seem to have random out of nowhere growth spurts. The female is chubbier than the male, but he's bigger than her, longer by about an inch, she, however, is thicker bodied and doesn't look small at all. Just smaller than him. In normal cases I'd say she'd be bigger than the common sized males, but she may not be common sized herself since she passed the four inch mark. I have seen no difference in color, the females of this species seem to be just as, or almost as bright, they have different fins and their body shape is a tad different, usually appear chubby too.
But yeah, set up your 29 gallon and go for it like Jim said. You may pull it off, just treat him or her good, alright? :3