I've used Photoflex 60" convertible umbrellas as shoot-thrus (without the black backing) and liked the results. But, I recently discovered the Paul C. Buff PLM system. I use the 64" Soft Silver with 8mm shaft for $50 plus the white diffusion fabric for $16.http://www.paulcbuff.com/plm.php
I also have the Photek Softlighter. Frankly, I was disappointed with the Softlighter. The fabric keeps coming off and it's tedious to attach the diffuser. However, is does offer good light and is relatively light. I save mine for overhead use with a boom.
The PLM remains my favorite system. Very quick and easy to setup, great color balance, more efficient than the Photoflex umbrellas, and very even lighting. It is heavy than the Softlighter. I highly recommend heavier stands.
For indoor, small rooms, I use Photoflex stands (7 or 8 foot). But, my favorite stands are Cowboy Studio heavy duty 12' footers. I think the model is 806D. They are heavy duty, with all metal parts, and they handle the 64" PLMs well at full height. They do have a longer than usual top spigot. I had to cut short 1/2" PVC pipe to make a bushing to fit around the indentation in the spigot so the swivel mount would fit better -- not a big deal. I can't vouch for all Cowboy Studio stands and suspect that shorter ones are cheap. But, these big boys work great.
Try the Manfrotto swivel mount 026 ($35).
Lastly, I recommend the Yongnuo 622C remote triggers. These are actually transceivers that act as both transmitter and receiver -- it doesn't matter which one that you use in the camera shoe. They run about $80 per pair. With these you can remotely control the flash settings with your camera's menu. (Note, I use manual exclusively, so I can't vouch for TTL with these.)