Need more info about the space you have available. A typical grow tent is 4x4. Use that as a standard - can you fit it? Or do you need something smaller? Or bigger?
A 4x4 is big enough for one plant or 16. One plant in a bigger pot grown with lots of training and topping will fill the 4x4. Or 16 plants in small pots in a
Sea Of Green config - fills the same space.
The difference there is one plant takes a lot of time training it, while the 16 plants are allowed to grow mostly untouched for speed. Also takes 15 more ($$) seeds for the
Sea Of Green.
I've filled a 4x4 with 5 plants, and I found the center plant really impeded access to the back two for defoliating or any other maintenance. My current grow didn't just fill the 4x4 with only 4 plants, they got so tall I had to replace the tent with a taller one during flower!
So - the number of plants in a tent is controlled partly by time available to deal with them and partly by the amount of lighting you have. The amount of lighting is determined by the size of the tent, so you kind of need to nail down the tent size first.
2-3 plants - could be anywhere from a 2x4 to a 5x5 depending on how much training you want to do to the plants to spread them out.
Based on my experience, unless perhaps you are growing autos, get a tall tent. Modern LED lights want 24-36 inches clearance, so think about what space is left between the light and the top of a pot in a 5-foot-tall tent. My current tent is 8 feet tall (Gorilla Grow - I can recommend it).
Vivosun looks like they have nice tents too.
More experience - you seem to be looking for a kit including light and fan. I'd be wary of that. In one year I've already replaced everything in my first 4x4 tent kit - light, exhaust fan, controller, and the tent itself. (If you are in Phoenix I'll make you a good deal on it.) You are going to want to end up with an AC-Infinity fan and controller, so don't take anything less in a kit. The light - depends on tent size - don't get one that isn't bright enough. (My 4x4 kit came with a 240w LED, which I replaced with a 600w.) Shape of light needs to correlate to the shape of the tent too.
Water pump - what do you mean here? Sounds like you're thinking hydro or coco.