Dude, get a big tank. I had little tanks for ever and I enjoy my 58 way more than any of the small ones. and you can can score a sweet deal on craigslist.
I'm the opposite way. I started at 30g and am now 15 & below. Though I wasn't planting the 30...
I'll probably get bigger once I am living somewhere I plan to stay for a while. For now small tanks are good for short stays haha.