In the case of studio work, the old saying is you get what you pay for is standard. It doesn't mean there isn't decent equipment out there if you search.
I have heard some good reviews of Cowboy Studios though.
so my 2 cents
The ultimate light is window lighting. Nothing beats the quality of a nice big window (north facing is best) before photography painters used window light for hundreds of years
Try to use it as much natural light as possible even if its only part of your lighting setup
Softboxes (my choice) has softer light then umbrellas. your have more control over the direction of the light with softboxes.
The bigger the softbox, the softer the lighting. I would try to get a min. of 24"
If you choose to have a background, it will need its own light to eliminate shadows or keep the subject far enough away from it (which can be hard finding the space)
I only have a one person basic setup. I bought this softbox
Cheetah QBox 24 inch foldable soft box it is of very high quality for the price and the guy is super helpful. it doesn't have the speedlight holder so if you go with speedlights, you need to order this
Speed Pro Bracket
I bought it years ago so if you decide on this setup, contact them and make sure you get the right setup for your flash or contant lighting
there are a lot of good suggestion on this thread, so research and good luck!
let us know how you make out
Randy