How to Choose a CO2 system

Very interested in starting a pressurized CO2 system for a 75 gallon planted tank. What I mainly want is a mini system probably a paintball sized tank due to space limitations but not sure if these systems capable of enough generation for a tank this size, Many of the systems either don't give what tank size they can support or are for 40 gallon or less.
I also have been looking at just about every online source to purchase as well as Amazon and Ebay but after what I think is a pretty good deal I see that some include extra items needed and some do not. The ones that seem to include things like diffusers and etc. look pretty cheap and I don't want to have to keep changing things out. What gauges, hoses, diffusers, and etc. would you recommend and what do I really need? Never had any experience in this area.
Know of any good deals out there??
Thanks for any help you can offer

http://aquatek-california.com/co2-regulator-solenoid/#r-78

I've got the mini one. the one that uses a 20 oz paintball tank. it works fine for my 55 but I'm not sure about a 75. maybe two of them if you just want to stick to a smaller tank. It was fairly cheap. got it off amazon for around 80$ and its awesome. i fill the tank up about once a month and i dont even crank it up and it can saturate my water if im not careful.

I still need to post some pictures of my co2 set up and how my tanks look now a days anyway cuz they have totally changed.

I was using the fluval mini it work ok for awhile but to me the diy two liter bottles last longer add a tee an a small air pump an a diffuser that hold the carbon in an slowly realeases tried the stone diffusers keep clogging at so im using the diffuser from the mini an a two liter set up yeast sugar starch an baking powder last a week water guality has change fish are brighter swords are pearling java fern.has started rooting on wood an my loach stays out swimming since I added it no algae no film. An I run it all day an night. For a seventy five I would try fluval 88 it comes with a noid bubble counter. I like my lil set up it fills the two champers an the air pump helps break down the co2 . In the morning when the lights come on the pumps goes of an the plants supply o2 .

Still have not sprung $ for a CO2 system yet. I looked at the Fluval 88 but only rated up to 40Gal. I want to use on a 75. Looks like I need to spend few more dollars similar to what Angeladdict is using or bigger. I may try the DIY as you suggested but not sure if I want to use 24/7 as I read that CO2 at night possibly bad for fish if not sufficient oxygen supplied in addition. A regulated CO2 that comes on with lights is a little more to my liking I think.
Thanks for sharing

Heres a trick ive learned add more.oxygen on my 29.ive double air.flow I added a sixty to my already thirty gallon pump set those up on a night timmer itll kick on at night an off in the am im cureently getting 2 bubbles a second an im running two 2 liters bootles threw a difusser thats bubbles up to my filter intake diluting the co2 into the tank plants has jumped in a month water has stayed the same no big ph swing yet . Fingers crossed I ordered some more threaded refills plus some guick growers purple cabomba green cabomba an some babby tears , water lettuce the object of co2 is to supply fast growers an slow growers need more root supplement like swords anubias an basicly big leaf plants if your going to.use slow growers use co2 tabs or liguids its cheaper fast growing plants need more co2 because of there growth rate is faster. You also need to think of your fish if your pretty well stock an useing gravel you wont need it your fish will supply enough co2 an ferts. Me personally I would use two gallon jugs 3 cups per bottle of sugar some baking soda 1/2 cup divided in 2 2packs of yeast each bubble counter,air stone an a half gallon of water dived in 2 fill shake an watch the bubbles