Google is your friend. I wouldn't bother with a catch can unless you do it properly. The reasons why you have the set up in the first place it to draw out the vapor/moisture from the engine which is produced from the cooling down heating up of the engine (produces condensation) and blow by. By just removing both pipes and connecting to a catch can that air is just mushing about constantly in the engine, it'll just get wetter and more contaminated the longer it just mushed about. So I'd recommend having at least one vacuum source or don't bother changing the standard system.
That's not a guestemate to how much I used, that is what I used 42lt ish some times a little more, <1lt. some times a little less, <1lt. When I filled up thats how much fuel went in my tank not what the tank holds and yes it averaged 34.5 uk mpg.
I've got this one for sale http://i689.photobucket.com/albums/vv260/djlies/w7044_main.png Full control from the stereo. It's a kenwood kdc-w7044u http://www.kenwood-electronics.co.uk/products/car/cd_receivers/ipod_iphone/KDC-W7044U/details/ Want £50 for it collected.
Armtech do a simple one with launch control and WOT gear change but with any hard cut (spark) rev limiter you run the risk of taking out your ring lands