My dad has a Europa and an Elan +2, so I can talk a little about the Europa.
I think the driving position is a little awkward at first, but just get some skinny shoes and it's fine.
Getting in is not graceful, but there's a trick to doing it easily. Right leg in first, sit down, then pull left leg in. Once you're inside, there's actually quite a bit of room.
Fiberglass is not difficult if done correctly, you can get all the information you need to know from an aircraft supply company like Wick's or Aircraft Spruce. The have videos and instruction manuals as well as raw supplies.
The Europa had a full restoration about 22 years ago, and it's been incredibly reliable. The only problems my father has ever had with his Lotii (he's had 5 total) have been where DPO's have gone in and messed something up.
Parts are not too bad, as the Twin cam is basically a tarted up Ford Kent. Watch out for water pumps. Front suspension is Triumph Spitfire and Vitesse, but very early Spitfire.
The car does not leak oil. Never has. Take some care in rebuilding the engine, and yours won't either.
Driving the car is like drizzling honey on Keira Knightley. It's absolutely the most sublime handling car ever. Not at all tricky at the limit. When it breaks loose, it's just to the understeer side of neutral. No tendency to swap ends, and it's actually very controllable in a 4 wheel drift.
With a Dave Bean Stainless header and exhaust, the car sounds great. It's very quiet, but muscley sounding.
I will say that there is a serious problem with the Stock Alloy wheels. They are lug-centric rather than hub-centric, however the lug holes in the wheel are not tapered which allows for some wear and a wobble above about 60 mph. So we made an insert for each wheel to become hub-centric, and they are great now. Panasports also work well and look great.
Club support is excellent as well. A good full-color newsletter with lots of tech articles.
Ok, that's probably enough for now. Here's a picture of the Lotii together: