plumbing questions

[motoman]

I've got a fluval 204 and a 304 and I'm looking to replace the tubing on both. I'm using my 304 on my 37 gal build project and I'm wondering what types of tubing people have used to replace the original gray tubing with? I'm also linking a co2 reactor and an inline heater to my filtration system. From what I can see I need 5/8" inside diameter tubing for the filter connections both where it attaches to the canister and for the other parts inside the tank (inlet/outlet), my reactor and heater both take 1/2" inside diameter tubing. Should I go with reenforced tubing (looks semiclear with white nylon line in it) or just clear tubing? Are there shops besides HD/Rona etc that carry a wide variety of these products and fittings that people would recommend? Pics of peoples plumbing would be great too!

Thanks.