I've got a RIS conditioning in a keg at the moment with a stave of american oak in it.
You need roasted malt in there and a metric shedload of it. The recipe you have will make a brown porter with an OG of 1.071, not even close to a RIS.
I cant convert my RIS to a kit recipe as it uses a lot of brown and amber malt which need to be mashed with a large amount of base malt.
Here's a recipe i made up on the fly.
1 tin Coopers Stout
1 tin Coopers Lager
2kg LDME
1kg dextrose
500g choc malt
500g roasted barley
No need for flavour or aroma hops in this beer, its all about the malt and roast. By using 1 tin of stout and a tin of lager it enables you to get the IBU high enough to balance the OG. In this case, 81 IBU which sounds like a lot but will be happily balanced by that much malt.
Yeast - if using a dry yeast then i would suggest Nottingham as its attenuates well and you dont want too high an FG in this style otherwise it will end up sweet. 2 packets. S-04 might be ok, re-cultured coopers as well.
The easiest way to get enough yeast for this beer is to use an entire yeastcake from a previous beer.
A RIS isn't for drinking a few months down the track, it needs at least 6, if not 12 months before its ready and the rough edges smooth out. I tasted some of mine on the weekend that has been in the bottle for 5 weeks (bottled 6 bottles as i had too much to fit in the keg) and its horrid, very unbalanced and harsh. Exactly what you would expect but i like to see how a beer (or wine) changes in flavour as it ages. The rest of the RIS in the keg wont be bottled for at least another 3-4 months on oak and then be put aside to next winter at the earliest.
For some information about this style of beer have a read of the BJCP guidelines -
LinkThe local BJCP study group recently did the porter and stout session and tasted 5 or 6 commercial RIS. Amazing beers!