I have an uncylced tank... well 2 uncycled tanks, with filters. Surimi gets upset when his is turned off, and i didn't have time to cycle it. I suspect its fine, no problems so far and its been a few weeks. I have learned that the filter makes it easier to forget about the waterchanges (guess what I am doing tonight...)
The gravelvac is a good idea (i got mine for $6 at petco, and drama uses a ATurkey bastor ($1 at the dollar store) SInce you wouldn't believe how much yuck is in the gravel... but try using in in the sink first, its kinda hard to get the hang of...