OK, let's try again then
Where did you get the recipe? Looking at the ingredients you've got there, you're going to end up with a strong stout getting into imperial stout territory, not a porter. There's far too much darkness and roasted flavours going on for it to be a porter, IMHO.
If I put those ingredients into BeerSmith I get an OG of 1062 and an estimated alcohol content of 6.6%.
If you want a porter like JS, I'd try something along these lines:
1.7kg Coopers Dark Ale
1kg light dried malt extract
200g Chocolate Grain Enhancer
200g crystal grain
12g Goldings finishing hop
12g Fuggles finishing hops
1 x Safale S-04 yeast
That gives you an OG of 1049 and an estimated alcohol of 4.8%.
Goldings isn't something I'd use in a darker beer so I may up the Fuggles to 20g.
Is the "chocolate grain enhancer" a prepackaged thing from your homebrew store? If so, I'd find a homebrew store that will crush grain for you on the spot as it's likely to be much, much cheaper than buying these prepackaged "enhancers" and probably fresher. Likewise the finishing hops. Are these the "tea bags"? Instead, find a homebrew store that sells hops in vacuum packed foil that is kept in the fridge. It's going to be cheaper and will probably be fresher. Any you don't use just seal up well and keep in the freezer.
Two things about the method: add the grain to cold water and slowly bring to about 70C and leave for 20 minutes then strain. DO NOT boil. Also, try and ferment at 18C-20C for the best results.
Cheers,
Oliver