The model of your distributor should be stamped on the alloy body (Note this one is a 23D4)
As for Electronic Ignition, personally i've had a few different types over the years but the one i prefer is the Lumenition Magnetronic system with the MS4 ballast coil (running a cold start hot wire from the starter solenoid) as i have fitted to my Sprint.
I have a Lumenition Optronic on my +2 but you need to fit a big control box which is unsightly and frankly an un-necessary pain, i've also had a Pertronix and a few AccuSpark's (cheap Chinese Aldon copies) but they didn't work out (Pertronic fail was my fault as i managed to ground the + when it was running by accident which blew the ignition, but the Accuspark just failed one after another).
As for plug leads etc there are a few options here, some prefer the more original Copper type leads but i went with 8mm Magnecor leads on the Sprint, mainly because they did a kit for Lotus Elans that routed through the hole in the back of the head rather than between the carbs and i preferred that look.
I actually still have the 8mm Accuspark leads fitted to my +2, they work fine and cost me about ?10 for 5x universal long leads. So i just ran an 8mm drill down the dizzy cap so they fit. The only problem with the cheap leads is the Silicone is a bit soft so i keep nicking them.
The one thing you need to read up on is the Rev Counter, some rev counters need an Rvi-Rvc conversion when swapping to Electronic ignition and some still work (seems to be a bit of a Roulette), but if you find your Rev counter stops working look into one of these
https://www.spiyda.com/magento/index.ph ... board.html