New 3D Mag P7 project -advice needed on P7.

I have a 3D Mag with an old Terralux 3w fitted & after reading lots of threads on here on P7 mods, I've ordered some of the parts I'll be needing.
I've read many of the P7 Mag mod threads & have learned much - wouldn't have known where to start without TBH .
So far I've ordered the heatsink from H22A here:
https://www.candlepowerforums.com/threads/203235
a UCL lens & some 22 gauge wire.
I'm intending to initially run it as direct drive using 3x D alkalines with a view to converting to Li-ion (18650 or C cell lithiums) later.
So, where can I source a D bin P7 emitter? AFAIK, I need a fv of 3.5-3.75v for direct drive. They seem to be scarce enough .

Photofanatic doesn't have them & the only place I can find them, if it's the correct one, is Kaidomain, here:
http://www.kaidomain.com/ProductDetails.aspx?ProductId=5485

Is this the right one? Good tint/bin?
If not, what/where can I find what I'm looking for?

Moving on.......
I like the idea of having different power levels available so quite open to suggestions of a suitable driver(s). Obviously, that scuppers the direct drive plan but it's easy go with/without driver so a nice option to have.
Something basic with lo/med/high would suffice, no strobe needed etc.

Finally, what's the best option for going li-on? Battery holder + 18650s or C li-ons or even D li-ons? Ideally, something chargeable by a Pila IBC (don't mind modding the charger/making adapters/extension cables etc.

I'll get some pics up as & when I start it. It will be my first modded torch & I'm sure the first of many .
Great forums & TIA for any wise words.

shdwkeeper on cpfmarketplace is selling some DSWOI's...

from the posts i've read here you really don't know what you're going to get when you order from KD.

Yep, I had seen the DSWOIs but was thinking the DSWOJs would be better for direct drive.
The only place I can find the J bins is at KD but I've never dealt with them before & would rather order from someone here on CPF :thumbsup:.

I'll probably order some I bins from shdwkeeper & go with 3D alkalines direct drive for a start & look at rechargeables later - C/D NiMH or LiION with drivers etc.
I just checked my Mag with 3 D alkalines driving the Terralux led & am getting just 3.3v @ .85 amps so should be no problem for an I bin DD for the moment.
Waiting on the DHS heatsinks/UCL lenses & anxious to get the emitters ordered up.
Thx for the reply :thumbsup:

No doubt I'll be back soon for some help!

Ordering a few I bins from shdwkeeper unless anyone has any other suggestions?

I would go with those. 3D voltage will sag under load and should still be safe.

Just ordered a couple :thumbsup:
No doubt I'll be itching to upgrade again from 3D alkalines. Will they still be OK with 3x D NiMH & a D2Flex. I'd ideally prefer something LiON (chargeable by a Pila IBC) but better than 18650s or are the NiMH the best option?