New RO System advice

Hi all

Finally going to update my ro system from my current 300gpd pure freedom setup. 

After researching on the forum it seems the best way to go is a  4021 or 4040 system which I shall probably need to add a booster pump too. I don't really have space for a 4040 so pretty  sure the 4021 will be more than sufficient as I work on my own.  

I have also taken others advice on here and looked on the Daqua website with a view to ordering from there as they come recommended.

My question is really to do with the housing that it comes with and the need for a pressure gauge.

On their website the 4040 kit comes with a stainless steel housing and does includes a pressure gauge amounst the other list of stuff its supplied with.

The 4021 however is supplied in a Champ housing which I assume is the plastic one in Doug's video and there is no pressure gauge listed as included.

So could anyone tell me the reason/benefits of the stainless steel housing over the plastic one.?

Am I right in thinking a pressure gauge is essential to get best out of the setup?

You can buy the 4021 stainless steel housing separately on the site but by the time I add that and a gauge it would end up being the same price if not more than the 4040 kit which doesn't seem good value.

Any advice before I spend my hard earned cash would be appreciated!!

Thanks

Personally I would go for the 4040 rather than the 4021 more surface area on the membrane so in theory should work better and last longer 

The plastic housings are no longer manufactured reason why we only sell Stainless Steel ones now. All set ups come with a pressure gauge which I feel is essential to measure the performance of your membrane.