Yeah I have a 190 too but it's for still gear, and I'd say it's borderline acceptable stability for that (I don't even have really big heavy lenses). If you're looking at Manfrotto then definitely get a 055 or better. I wish I'd got a 055 now because I rarely travel far by foot with my tripod so the weight isn't an issue and it's a lot studier.
Get a decent head - equally or more important than your legs. I use a ball head for stills so I can't help you there but do your research.
If you're serious about your filming (and I hope you are if you've got a 2100), then lay down the cash on the very best you can afford, or save up for the best - you'll only end up buying it eventually anyway so save yourself some time and money and buy it now.