Searching for diaphragm air pump

Hello. I have been doing lots of searching for a medical/food quality (oil and other contaminant free) diaphragm air pump online. I have found some suitable matches but I figured I would reach out on this forum to see if anyone has any input. The general specifications I am looking for:

rough dimension requirements: 10x10x6 cm (the dimensions can vary, must occupy roughly that volume) desired flow: ~6+ LPM pressure: low pressures are fine. My particular application does not require high pressures at all. electric motor operated (DC or AC) Also, I'm hoping to find a pump for $100 or less. If anyone knows of any suppliers that sell small quantities (ideally min order of 1) or has any other inputs please feel free to reply.

Two possibilities come to mind (provided this is for AIR only):

  1. Aquarium air pump (cheap)
  2. Nebulizer air pump (expensive if new - cheap if bought used)

For #2 - a nebulizer is a pump used to turn certain breathable pharmaceuticals into a mist for someone to breath (for instance, albuterol for asthma treatment); brand new they can cost a bit (usually, they are a prescribed device), but I see them quite often sold at thrift stores. Find one that is fairly clean and such; you don't have to worry about body fluids or anything (usually), because the nebulizer is hooked up to the breathing portion by a long plastic hose. They tend to have good output (better than an aquarium pump), and tend to be fairly strong - though they are much louder than an aquarium pump - mainly because they are an actual piston pump (again, usually), rather than a cheap diaphram pump.

Both pumps are usually AC only. A nebulizer pump may or may not fit in the dimensions you have given (even if you removed the pump from its case), but an aquarium pump should fit easily.

I have looked at a few aquarium air pumps that seem like they may be suitable for my intentions. My main concern is finding a pump that will fit in my required dimensions and still provide the necessary flow rate. I have been able to find some very high grade pumps but most of the ones I have found have a correlation of increasing flow rates to increasing pressures (high pressures are not needed) and this tends to drive the cost way up. I may be looking for something that does not exist in a mass production market (maybe require a custom order). Or maybe I will have to utilize 2 or more smaller pumps which I have considered.