I have this tub at the place I work right now (
Master Equipment Everyday Pro Grooming Tub/Cabinet | PetEdge.com). It's one of the cheaper tubs because its a petedge brand. It is plenty big for your BRTs. I have washed St. Bernards, Bernese Mountain Dogs, and English Mastiffs in it with no problems with them standing up or turning around. It measures 48" x 24 1/2" x 56". I think its a pretty standard size. The tub is made from 16-gauge zinc-plated, powder-coated steel and is held together by rivets and silicone. Personally I hate this tub. It came with an above cabinet which my boss attached and i find it annoying and in the way. The tub also has a few small leaks in the corner area because the silicone caulk must wear away from being disinfected so many times. The bottom of the tub has discolored. The plastic rack it came with for the dogs to stand on is hard to clean and builds up mold/mildew or whatever. These are the types of problems you are going to find with a cheap tub.
Other places I have worked at have tubs by Forever Stainless Steel (
Forever Stainless Steel). They are made of thicker gauge steel and are welded together (no caulking and no leaking). These tubs are expensive.
Other good tub makers:
UltraLift, Inc. Petlift*::*Tubs Stainless Steel Grooming tubs & tub (41303) - Stainless Steel pet wash with ramp / ramps for Professional pet Groomer at Hairvac.com,* Hanvey Specialty Engineering, Pet Grooming groomer Equipment, LIPS system, Taxi Vac clipper vacuum attachment sytem Pet Grooming and Veterinarian Equipment by Edemco Tubs | Groomers Best
Since you are only grooming your personal dogs and not bathing multiple pets a day you might be ok with just getting a pet edge master equipment tub. It all depends on what you want to spend in the end.
At home, for my personal set up I have a regular utility skin for the washer to drain into. I keep it clean with fantastic bleach. If i do a neighbors or friends small dog at my house I will wash them in there. I also have a Large Booster Bath Tub (
Official Home of the Booster Bath Elevated Plastic Dog Grooming Tub for Home Use) that I can place in my walk in shower in the basement to wash medium/large size dogs in, or i'll just wash them in the shower without the booster bath. The booster bath is good for washing outside in the warmer weather too.
As far as nozzles go, most groomers I know just go to Lowes and get a garden "fire nozzle" style sprayer. They have different settings to adjust the spray. You need good water pressure though for any type of nozzle to work well. For a great, powerful, undercoat removing nozzle I highly recommend the SavUrFur Nozzle (
SavUrFur Shopping and Products | Save 10% when you order our shampoo and conditioner bundle) but again its expensive for just regular home use.
If you get a grooming tub and also use it for the washer drainage I would highly recommend a good hair/lint trap to make sure hair and lint don't clog the drain. the tub i use at work has something like this in it (
PetLift Smartway Hair Trap | PetEdge.com). Not sure if it came with teh tub or if my boss purchased it separately. There is also this one
Hair Trap | PetAgree Grooming Supplies.
Just my opinions. If you have any other questions feel free to ask, though i must mention, after joining facebook, i am terrible about coming on YT anymore.