What's your budget to spend and power goals and intended use (street car, track, hill climbs etc?)
Sounds like you have some nice mods already, definately get a FMIC & CP. I highly reccomend catless DP's I honestly didnt notice much more of a smell, but they're louder on cold start ups but engine response is so much better with them installed!!
As for RB's they're awesome, but maybe see what the car feels like fully setup and tuned on E85. That may be enough power for your intended use!
E85 is great stuff, and yes as you mentioned to run it safely and to maximise the returns our fueling systems require an upgrade.
The best option is to purchase a stage 2 fuel it drop in bucket which has an upgraded lpfp integrated making it a pnp solution and comes with excellent after sales support and install info. Basically the fueling system has two pumps, the LPFP supplies fuel to the HPFP, and the HPFP pumps fuel at extremely high pressures required for the direct injection setup.
If you think the hpfp is on its way out, maybe just install the stage 2 LPFP drop in bucket wack in some E85 and start logging paying attention to your HPFP pressures. If it's lagging behind under WOT conditions replace it with a fresh item. The vargas HPFP upgrades (single and double barrel hpfp upgrade) are only really required for cars that are 350-400rwkw +. If that's your target those and the motive port injection setup are the fueling upgrade options available.
With a JB4 I'm pretty sure the guys run a backend flash, but either way the BMS forum will help you with your logs if you postup the details on their forum
I've recently had a fresh hpfp, stage 2 drop in bucket running an OTS cobb E30 map and my car managed 309 rwkw (I'm FBO minus meth & running the stock turbos).
With an E50 mix and a custom tune it should be punching out some really good numbers, negating the need for RB's for a little while longer
