Source for air suspension parts and tools?

All available off eBay at a lower price and better quality than the huge markup ‘air ride suppliers’ have.

I buy quite a lot from Context pneumatics, but it’s easier to search eBay to buy off them.

Biggest thing is don’t think you’re tied to 1/4” or 3/8” lines. If you’re doing a full install it makes way more sense to sell on any fittings that size you have and use 8mm or 10mm over here, especially 10mm as you can buy pressure rated seamless alloy tube for doing hardlines much cheaper as it’s used in central heating systems. That means all your tools for cutting and bending as also super cheap and you can get em from screwfix of you need them immediately- same with connectors for emergency repairs.

PTC fittings are a lot more reliable then they used to be, especially if you’re buying brand name like PCL or John guest. But, it’s all down to the specific application. Sometimes you have to use them as you can’t get to a Union to tighten it. PTC are more picky about tube cuts and deburring than other types of connector. Sometimes you just get a bad one that won’t seal so spares are a must.

If it’s your first system I’d expect you to underspec it, get bits wrong, and have problems, especially on the type of car you’re doing as some parts of the system will always be a compromise. but that’s how you learn. Ultimately doing a system properly isn’t cheap, but conversely that doesn’t mean the expensive stuff is best- the ta quite often not.