Before you start... some considerations:
Eurorack percussion set-ups are insanely expensive compared to buying a drum machine that can sync or receive input from Eurorack. There's nothing wrong with doing percussion in Eurorack... it's just going to cost a pretty penny.
Let's work from the end and work our way backwards.
You'll need an output module that can deliver a stereo line-level (not Eurorack level) output.
You'll need a mixer for all of your percussion inputs. It's best to have one that is stereo and has at least one send for reverb or effects. The Endorphins has a mono sum mixer for its internal sounds... but if you use it, then whatever is in that module is a mix of percussion and has to be treated as a whole.
You'll need a way of triggering your drum modules (Eloquencer will work nicely).
With that... your set-up is missing a main mixer. You'll need a minimum of four inputs. More if you want the individual outs of the Endorphins.
LFOs are useful. But how do you intend to use it in this set-up?
The FH2 will work as an alternative to the Eloquencer if you're working with a DAW. However, the FH2 has to be set-up in advance of the DAW as the FH2 doesn't like to be addressed by the browser GUI and your DAW at the same time. So to change the FH2's settings you'll have to quit out of your DAW.
This set-up is about $2,000 - $3,000US. If you use an off-the-shelf MIDI drum machine with a Befaco VCMC to translate from CV to MIDI you'll spend a whole lot less. If the drum machine can respond to MIDI CC the VCMC can translate from CV to MIDI CV.
Consider your options carefully.