The upgrades for the TM L96 will not fit the Well L96. The TM uses some VSR parts and some that unique. The Well L96 uses APS-2 upgrades.
I have this gun, and have recently upgraded it. Put about £520 into it and it's just about done.
Mine was cr*p accuracy with the stock barrel, as it wasn't cut properly, but my mate's has good accuracy with the stock barrel.
If it's the version 3 (with velocity reducer), then you won't be needing power upgrades yet, but you'll probably need to strengthen the trigger unit and sears. After just three games, mine had a crack down one side, and on both the screw holes, so I bought the metal one from Airsoft World (
here), I haven't replaced the sears yet though, as they're hold out at 500 FPS.
For accuracy upgrades, I got the hop unit from ASPUK (
here), which is more consistent and allows the use of AEG barrel. But it is not compatible with the stock cylinder and head. So, you would to get new ones, I got the ones from ASPUK (
here and
here), but you can't use the velocity reducer with these.
The hop rubber I got was the MadBull Red one, which I wouldn't recommend as it gave me far too much hop for .40s. So I'm going to get a standard Tokyo Marui one and nub, as the hop unit is designed for.
For the barrel, I got the MadBull 6.03x650mm from Action Hobbies (
here), which is longer than is needed (the stock is 495mm). I used silencer and adapter to hide the extended barrel.
For power upgrades, I got the advanced upgrade set (spring, spring guide and piston) from ASPUK (
here) which replaces the plastic parts with more durable metal ones, and can supposedly withstand 600 FPS.
Bear in mind, this is the cheap route for upgrading and cost me ~£500 (including gun).
The other route is PDI or LayLax upgrades, costing a lot more, but being more durable and consistent, but I'm happy with the cheaper route.
Make sure you check compatibility with the rifle and other upgrades before you buy though!
Hope I helped

.