Dude you have the concept down.. Go to Walmart and get this shit
Aqua Culture 5-15 gallon one outlet airpump - $6.77 (the double outlet is $10.52 - would be best for two 5" airstones)
One or Two Aqua Culture 5" airstone - $1.63
Aqua Culture 25' airline - $2.83
And a rez, they have so many damn plastic tubs at Walmart, and so many of them are perfect for bubbleponics. They carry something that is about 1.5ft long 5" high x 5" wide for $2 bucks, you could easily fit 2-3 plants into that with close to no floor space or height taken from your cab.. Netpots can be literally anything.. from party cups to yogurt containers, find something that has a strong rim around the top
That right thur is a cheap as hell - decent quality bubbleponics system, that I will bet would work 100% for you nig